srikanth9502 wrote:

The average American spends y dollars on food per month, except during January, when food purchases are x percent lower than they are in other months. Which of the following reepresents food purchases, in dollars, for the first 9 months of a year?

A)9y – xy/100

B)9y + xy

C)9y – xy

D)(9y-xy)/9

E)y-xy/6

Assign values.

Let y dollars per month be 10

Let x percent less for January be 10

Eight month total is (8 * 10) = $80

January total is (.90)(10) = $9

Total for nine months = $89

With y = 10 and x = 10, find the answer choice that yields $89.

Answers B, C, D, and E can be eliminated quickly.

Answer B is 9y + xy. 9y = (9*10) = 90 is too high already. Adding anything will make it higher.

Answer C, 9y – xy. Easy and quick calculation shows result is negative.

(9*10) + (10*10) =

(90) - (100) = -10

If C is negative, then Answer D, (9y-xy)/9, is too. Its numerator is identical to answer C.

If C is negative with (

9y - xy), then Answer E's numerator,

1y - xy, will be more negative.

Answer A, which initially looked strange because I read the denominator incorrectly, remains: 9y – xy/100

(9 * 10) - \(\frac{(10*10)}{100}\) =

90 - 1 = 89

Answer A

_________________

Life’s like a movie. Write your own ending.

— Kermit the Frog