Question

Monique needs to buy a baseball for $20, a soccer ball for $15, and a set of tennis balls for $12. Monique has a coupon that gives her a discount of x percent on a baseball. She has a second coupon that gives her a discount of y percent on a set of tennis balls. The third coupon gives her a discount of z percent on her total purchase. She cannot combine the coupon for the total purchase with the other two coupons. These expressions give both possibilities for the total cost of Monique's purchase after the coupons are applied, the variables represent the percentages as decimals. (1−x)20+(1−y)12+15 (1−z)(20+15+12) Which part of the expression represents the price of the set of tennis balls after a coupon was applied directly to them?

Answer 1

(1−x)20+(1−y)12+15

(1−z)(20+15+12)

Answer 2

12(1 - y) and 12(1- z).

Explanation:

Cost of a base ball = $20

Cost of the base ball after a discount coupon of x% = $20 - x% of $20

= $20(1 - x)

Similarly cost of a tennis ball with y% discount = $12(1 - y)

And cost of soccer ball = $15

So the total cost of Monique's purchase = 20(1 - x) + 15 + 12( 1 - y)

Here 12(1 - y) represents the price of the set of tennis balls after coupon z was applied.

If other coupon of z% is applied on total purchase of Monique, then the cost will be = (10 + 15 + 12) - z% of (10 + 15 + 12)

= (10 + 15 + 12)(1 - z)

In this expression 12(1 - z) represents the cost of a pair of tennis balls after z% discount on total purchase.