Question

At the Moore's Mart, a bag of Doritos costs

$4.00 and a bag of Cheetos cost $4.25. A total
of 10 bags of chips worth $42 were sold. How
many bags of Doritos were sold?

Answer 1

2 bags of Doritos were sold.

Explanation:

Let,

x be the bags of Doritos sold

y be the bags of Cheetos sold

According to given statement;

x+y=10 Eqn 1

4.00x+4.25y = 42 Eqn 2

Multiplying Eqn 1 by 4

4(x+y=10)

4x+4y=40 Eqn 3

Subtracting Eqn 3 from Eqn 2

(4.00x+4.25y)-(4x+4y)=42-40

4.00x+4.25y-4x-4y=2

0.25y=2

Dividing both sides by 0.25

`(0.25y)/(0.25)=(2)/(0.25)\\y=8`

Putting y=8 in Eqn 1

x+8=10

x=10-8

x=2

Hence,

2 bags of Doritos were sold.