ngu2587

A can do a certain job in 12 days. B is 60% more effecient than A. How many days does B alone take to do the same job.. The answer is given as below Ratio of times taken by A and B is 160:100 = 8 : 5 But I was thinking if B is 60% effecient more than A then the ratio would be like A:B = A:A+60/100A = 1: 160/100 = 100 :160 which is not the answer given above.. Now the original answer validates something like 8/5=12/x.. Supposing x days for B.. I did not understand the logic behind this too.. Kindly explain

Hey KillGMat, Even I couldnt understand the reply to the problem. Plz explain in detail.

Hi Sanket,g.tatiana, can you please explain me how did you come up with that answer

Hi GmatFundoo, Thanks for the reply. But I could not understand why they added 1. How do you think this problem is different from this problem as below A,B,C start at the same time in the same direction to run around a circular stadium. A completes a round in 252 sec, B in 308 sec and C in 198 sec, all starting at the same point. After what time will they meet again at the starting point. In this problem we just take the LCM, as per the logical explanation given by you.. Can you please explain me

Hi kluevehe As the problem says, a and b should be integer and a+b=5, let us first find set of integers which solve the equation a+b=5. For ex it can be a=1,b=4 or a=4,b=1.. next a=2,b=3 or a=3,b=2 Lets take into account negative integers too. a=6,b=-1 Taking all the above set of integers which solve the equation a+b=5 Lets check the first option i.e The product of a and b is odd. Now if you take a=1,b=4 or a=4,b=1 The product is 4 which is even. So eliminate this option Next option is If a is odd, b is even.. Now if we take this set of integers a=1,b=4 a is odd, b is even. c option can be eliminated out, because the first option is ruled out. d option, i,e II and III is the right option because even this condition i.e if a is negative, b is positive is true for negative integers ( a = -1 or b =6) Hoping that you understand the above solution.

Hey all, I was stuck up with this problem.. Six bells commence tolling together and toll at intervals at 2,4,6,8,10 and 12 seconds respectively. In 30 min, how many times do they toll together The answer for this problem is given as below L.C.M of 2,4,6,8,10,12 is 120 So, the bells will toll together after every 120 seconds, i.e 2 min In 30 minutes, they will toll together [(30/2)+1] = 16 times Now over here in this problem why are they taking LCM to find when the bells will toll together And the last line i.e in 30 min they will toll 16 times.. How did they arrive with that solution Please explain me..