[Music] [Music] yeah hi everyone my name is Ravi Prakash and we are continuing speed mass here the second class of speed mess okay see we will do this kind of four numbers here now in the last class we had done about all the percentage of approximations how to calculate numbers like any X percentage of some why this form we did right now in this class we will see how to auto scepter how to calculate if like numbers of the form suppose take example 233 upon 864 okay how to reduce value in within 10 seconds how to write value within 10 seconds right and by thinking not by any formula right just by thinking pure logical approach okay so see we have this kind of number here 233 upon 864 what is the value right for calculating this again we first again we should remember the major numbers right for the major numbers like one by one is hundred percent number is close to hundred percent or not half is fifty percent number is close to fifty or not 1/3 is 33.33% number is close to one-third or not one for this 50 for 25 percent 1/5 is twenty percent right like this one sixth is 16 at least by one by six you can directly use you so you have to observe here that numerator what we are doing in this kind of question is numerator numerator is what percent of denominator correct why because if I write something like if I read something like 10 by 15 what is the answer here so already read suppose take it easy number farad 10 by 20 10 by 20 what is the answer here so what is 10 by 20 basically means word 10 is 10 is what percent of twenty ten is what percent of 20 that's it simple meaning right so - okay I know that 10 is half of 20 what is 1/2 half is 50 percent what is 50 percent 1 by 2 that's what you get after cancelling that that's what it that's what you get after canceling 1 by 2 so 10 is 50 percent of 20 that is half of 20 okay similarly here also very calculating 2:33 is what percent is what percent of 864 this is a question here 233 is what positive 864 right so to observe we also observe like okay is it closed - is it closed to any of these numbers like 20 percent or 16 percent or 25 or 30 3.30 or fifty or hundred right otherwise what we do if it is not accepting any of these numbers you have to go away approach of 10 percent calculating 10 percent and then calculate C around 10 play around 10 percent right play around 10 percent up is forget this is 10 percent then how to create the other number that we will see but here we know that see just a simple approximation it is 200 something it is 200 something it is 800 something so 200 is how much what fraction of 800 around 1/4 so first filling is it is around 1/4 around 1/4 what is 1/4 25% 1/4 say 25% that basically means that now once you got his logics will calculate ok what is 25% of 864 exactly so 25% of 864 is how much it is how much 25% of 864 dammit 1/4 what is 1/4 1/2 of 864 is what 432 but is how what is half of us are you do to 1/6 right double of 25% is to 1/6 we got it right but but what we need is what we need is 233 that means I know that okay my answer is little bit more than 25% right this we know now that 233 is around 1/4 of 874 if I calculate exactly if I calculated exactly 1/4 that is 25% it is 2 and 6 that means my ass it is numbers 233 years that means my answer a little bit more than 25% how much more 17 more now 17 is what percent of 25 sorry it's 864 now 17 is what percent of eight city for it it's like what we are doing is say we are breaking it 6 to 16 player like you but it's breaking this 864 s to 6p by eight sixty four plus seventeen by this like what we are doing here plus 17 by 864 okay this is okay this is one by four because we found out of one by four twenty five percent okay now what is 17 over at 64 so again 17 is much less than in 64 good one on one person what is one positive basis with 864 so one percent of 864 is how much it is a two point six four forty 17 / - seventeen I don't double around it double just double it right around double how much it is two person so this 25% is to present right approximately 17 point two to be exact but okay I get take 17 what does answer now cell is 27 percent what is the value value is point what is 8 percent 0.27 for 27 percent is about 20 cent by 100 that is 0.27 so that means 233 upon 864 what is the value of this number it is point two seven approximately very close point two seven okay this is a holter will do a whole way to do it right just search that numerator and searching for numerator is what a percent of denominator okay so if numerator is what percent of denominator that basically means that okay 233 is what position up at 64 so we saw we observed that it is 200 something it is ated at something it's around 1/4 so around 1/4 miss what around 25% okay if we calculate it exactly 25 percent that is 1/4 it comes out of it - once it comes it comes out to be 2 1 6 now 17 more to go 17 more to go okay so if 17 moved over that will go to the number 233 so what is 17 how many percent of 864 so 864 one percent is what eight point six four it's around double 30 17 point two eight right so twist around double so 25 plus two and same person what if it is in percent is 27 by 100 that is 0.2 seven okay whole logic behind it right I hope it is clear up this point yeah so remember I did a search for around these numbers here to search around these numbers right right here remember it one by one is 100 percent okay one by two is 50% her to search around these numbers 1 by 3 is 33.3% 1 by 4 is 25 percent ok 1 by 5 is 20% 1 by 6's sixteen point six six percent right around what is one by seven fourteen point two eight percent this one by eight twelve point five percent so I don't have to play these numbers right okay take another example like it is for one for upon 869 okay for one for upon eight section in what is the first interest value approximation what is the value right so we'll do in percentage this question is it basically means that for 1/4 is what percent of 869 for 1/4 is what the percent of 859 right it is what position is the first thing means against searching for this around 1/2 around one third around 1/4 what right you see it is 800 something it is for head something to do around 1/4 it is around sorry to around 1/2 right it's around 1/2 so what is half of this Timon is at least I know what it is ok it is around 1/2 around 1/2 means around 50% what is half of this number is actually so 869 half is how much 400 34.5 correct 800 1/2 is the 459 1/2 34 points a for 34.5 is how much it is so for thirty four point five how many does 50% whatever it is what is my number here 4 1 4 that means I'm sure that my answer is less than 50% my answer is less than 50% right in many cases in many cases you can directly get the answer also in many cases you can directly get the answer also right very flexible options are 46.7% ok or 51 percent or fifty six percent or fifty nine point three percent is kind of number officers are there so here you know that it is around less than half what is less than half only one option right go to option B option approach right but but now we will see exactly to solve is six after Tucson that is there are closer options also we can easily mark the answer so what is for 34.5 it is 50% around 50% right now I know that it is bit less than 50% how much less in number in number is less than 20 so how much does in % is so basically 20 is what percent of its 69 okay so 869 what is 1% is eight point six nine to approximate to one point I can take as eight point seven so 1% is 8.0 8.7 right what is 2% seventeen point four okay it is 20 here so if 2 percent is seventeen point four another two point six to go another two point six to go so if one percent is eight point seven what is 0.1 percent point one point it is helmet it is 0.87 okay 0.87 right so you can again approximate to one pillow decimal reading it is 0.9 0.9 0.1 percent is 0.9 okay - and very carefully furnished a point one percent is 0.9 sorry point one zero nine point one percent is point nine okay what is two point six roughly three times roughly three times it is approximately 0.3% 0.3% right what is the answer here 2.0 T what is twenty two point three percent is 2.3 percent fifty percent - two point three percent what is our cell 46.7% right again very carefully understand is every process every step unit I need to understand to do it firstly because all the systems which I'm screening in detail our mental block we will do mentally when you do mentally you'll face difficulty at these steps and you stop there I don't want you to stop right this question is hardly a 10 second question right if you ask me how to solve it say I simply think like this half of this number is what this is close to half I know but is how it is number four thirty four point five okay around twenty less okay I don't twenty less than half right what is twenty now what is twenty now for 20s around around what is why one point seven eight point seven for just two percent seventy point for around two point three fifty minutes to point C for this point seven this kind of approximation will come when this all is it steps are mentally clear you'll not find any mental block at this attempt right all this should be absolutely clear right that's that same is feeling so much if doing so much right understand again so for one four is approximately half of this number right around 1/2 is searching so if you calculate exact half it is fifty per you how much for thirty four point five then again how much less it is just twenty list is to exact twenty point five hundred we can take twenty okay what a number is twenty four this person number what is one percent so 20 is what percent of sixty nine so it's one percent is eight point seven okay it's so I have to reach closer to twenty now so it's two point eight is seventeen point four okay how much is left after sending 0.42% further two point six is left because seventeen point four plus two point six will give me twenty is seventeen point four it is two percent fine but what is to burn since now so at the very last now is we should go for one person what is point one percent one percent eight point seven what is point of inversion further one disabled back okay this is nothing but this is nothing but point one percent let me write it clearly nothing but point to one percent how much it is 0.87 that is approximately 0.9 always goes always go to one piece of the symbol in approximation is easier if point one percent is four point one per head is 0.9 what is two point six around three times around three times what is Oh point three percent right so two point three it is two percent plus 0.3 percent it is two point three so fifty minus two point three how much sorry not forty six point seven I'm sorry it's 47.7% 47.7% I hope it is clear right I hope it is clear okay we'll do more and do more policy if I take this number now you see three seven three seventy three by you take around 12 196 ok 373 by 12 and this is what is the answer okay again the first approaches for checking is 373 is what percent of one two nine six okay it is around how much so you can see it 12 minutes something it is thieriot thieriot something so around 1/4 around 1/4 what is 1/4 25% what is it exactly then it is if it is around 1/4 in calculating to calculate exactly 1/4 of it but it's exactly 1/4 of it so 12 101 force is how much 396 what is 1/4 24 so 324 is exactly 25% of it it is how much more than that it is again what is how much more than that what tonight more than that 49 it is 49 more than that ok so it is 49 more than that now first thinking is okay what is one percent over twelve point nine six so what is one percent of test number twelve point nine six can take it in approximately thirteen only because it is almost thirteen okay to reach two closer to 49 for posit is how much 52 but let's subtract you know how to subtract 3 subtract frame is what is the what what is three out of one two nine six so four one two nine six one percent is one point two nine six that is one percent is one point with is thirteen what is point one percent it is it is how much one point three roughly 1.3 so if point one percent is one point three you can take three as roughly two percent 0.2 percent right it doesn't matter no beginning point two percent so one percent plus four percent - sorry not one person sorry four percent and then minus 0.2 percent 52 minus three forty nine we were searching for 49 52 minus three forty nine okay and four percent minus point two point eight is almost three point eight percent this number is how much it is three point eight percent twenty five plus three point at how much 28.8% what is the value except divided by one hundred twenty eight point eight percent so twenty eight point eight divided by 120 eight point eight divided by unavaatu the answer answer for this question how much point 280 so approximately equal to point two nine if you approximate to to place a decimal right this is a whole funda right behind it I think every step should be clear right simply do it in mind 373 upon one two nine six right 373 of one one two nine six so wonderful so dividing it it's 10% okay so no sorry no 10% you see this number is closed numerator is how much in a percent is among these major numbers 100 percent 50 percent 25 percent right it's close to how much so you can see here in denominator 1,200 something in numerator 300 something that means it is 1/4 of it what is 1/4 25% right so we calculated calculated exactly 25 positive one two nine six that is one two nine six what is the 25 percent 324 okay twenty-five percent how much is left so further for the nine to go okay for the forty nine to go what is forty nine point forty nine now so it is very small smaller than one two ninety six so get to one percent of it what is one positive one two nine six one twelve point ninety six twelve point nine six this is approximately equal to thirteen only if one pellet is thirteen I need I need to reach closer to 49 so I'll do four times that means four percent is 52 but while doing four percent I have come three extra subtract three what is 300 performed at is three now four one two nine six so four one two nine six is if one question is 13 so what is point one percent one point three further one decimal back then I plug in to approximately two times right what is point what is two times two point six what is three times three point nine which we can do 3s approximately two point two times right at this point two percent so point two percent it was for the subtract it subtract 3 subtract 0.2 percent so four minus point two three point eight that means 49 is three point eight four 2,800 all right this is one way this is one way to find the exact exact value correctly first thing if you learn all these things not is mind very very very good enough right second day for marking options right what to do see three if I have this kind of question three seventy three one one two nine six first thing will just write to my mind is okay not do that much calculation okay first thing is tractable mind is okay this one 437 25% so ok 25% is how much it is 3 1224 how much further for today in to go what is it 1% 1% is around 13 when it is 4% is 52 just less than 4% around 3.8 3.9 around 3.8 3.8 just less than 4% 52 what is my answer answer is twenty eight point eight percent or twenty eight point nine percent around this much right after 10 second position test if you understand all those things right for that because your mind will be absolutely clear when you know how's that process right you know to know the process and I can do a prostration based on your mind okay and if you get this to this thing within 10 seconds 99.9% chance is the options will be you can easily mark the option right suppose the options are like see it looks very closely at this options you see obviously will be like 28.6% 28.8% 30.1% and 30.3% in the force to go if you look at his options this option sore throat dot 30 head really far apart okay 29 make it in first go if you look at this options 29.1% and wonder nine point three and these two he looks very close but just after doing one step it is enough for me right because what I know that my answer is just less than because just less than 4% because 13 for x is 52 okay just less than force I should mark 2800 okay so this kind of thinking should go that if that clear thinking is is a you have that kind of clear thinking this is how you should go so I think you can do it easily this kind of questions right okay so we'll do next coaches a next video okay thank you you [Music]