amanvermagmat wrote:
Marvin spends certain sum of money on a fixed number of multi-vitamin tablets of brand X each month. All these tablets have same price. If in a particular month the price of each multi-vitamin tablet of brand X increases by 25%, by what number should Marvin decrease the number of tablets purchased, so that he does not want to change the money spent on purchase of these tablets?
(1) Marvin used to buy 80 multi-vitamin tablets of brand X per month before the price increase.
(2) After the price increase, Marvin would need to decrease the number of multivitamin tablets of brand X by 20%, so as not to change the money spent on these tablets.
Lets assume :
The price of each tab = p . Hence after price increase the price of each tab = 1.25p
# tabs used before price increase= x & # tabs used after price increase= y
As per the Q steam xp=1.25py ==>\frac{1}{1.25}* x= y ==> 0.8*x = y
==> the number of tablets to be used after the price increase is 80% of the number used before price increase.
To know y , we need information about x.
(1) Marvin used to buy 80 multi-vitamin tablets of brand X per month before the price increase.
Putting the value in the expression : y = 0.8*x = 0.8*80 ..............................................
Thus Sufficient.(2) After the price increase, Marvin would need to decrease the number of multivitamin tablets of brand X by 20%, so as not to change the money spent on these tablets.
This statement is exactly the same as our deduction. No specific information for x is provided . .....................................
Thus Insufficient.Hence I would go for
option A.