Question

Kylie and her children went into a bakery and she bought $10 worth of donuts and brownies. Each donut costs $1.25 and each brownie costs $2.50. She bought twice as many donuts as brownies. Determine the number of donuts and the number of brownies that Kylie bought.

Answer 1

4 donuts and 2 brownies

Explanation:

Guess and check

2 donuts --> $2.50

1 brownie -->$2.50

Since the amount of donuts is double,

we try :

4 donuts -->$1.25(4) = $5

2 brownies --> $2.50(2) = $5

Answer 2

she bought 4 donuts and 2 brownies.

Explanation:

This is a question on simultaneous equations where two variable are given with two or more relational equations. if she bought $10 worth of donuts and brownies, and each donut costs $1.25 and each brownie costs $2.50.

Then,

1.25d + 2.50b = 10 where d and b are the numbers of donuts and brownies purchased respectively.

if She bought twice as many donuts as brownies, then

d = 2b

Therefore,

1.25(2b) + 2.50b = 10

5b = 10

b = 2

d = 2 × 2 = 4

Hence she bought 4 donuts and 2 brownies.