sanju09 wrote:Suppose 7 monkeys take 7 minutes to eat 7 bananas. How many minutes would it take 2 monkeys to eat 2 bananas?
(A) 2
(B) 2.5
(C) 3
(D) 3.5
(E) 7
The best way to handle these problems which can be tricky is to use intuition. Formulas will lose u when the problem isTWEAKED. Always reduce it to amount of job done in a unit of time. 7 monkeys doing 7 mins gives 49 monkey - mins. Forget about the 7 bananas yet. This could be filling a drum, typing a paper etc. It is important for determining the fraction of the work done. You ALWAYS want to know how much time it takes 1 monkey to do the job in a unit of time. This important animal is 1/49 MON-MIN. So from here u can see that this important fraction can be multipled by a number with units MOn-MIN. The problem asks how many mins it takes 2 monkeys. So we get 2 monkeys times X mins which gives 2X mon-min.
2X mon-min./ 49 mon-min is some fraction of the job done.
2bananas/7bananas should be the same fraction of the job
Since these two fractions MUST be the SAME ( one is in units of mon-min while the other is in units of bananas and the units cancel). You are just looking for the X that MAKES them equal.
2X/49= 2/7
X=7 mins, since u were solving for time.
Last edited by
dtweah on Thu May 13, 2010 6:17 am, edited 1 time in total.
