Question

Keiko's Coffee Shop makes a blend that is a mixture of two types of coffee. Type A coffee cost Keiko $4.15 per pound, and type B coffee costs $5.25 per pound. This month's blend used four times as many pounds of type B coffee as type A, for a total cost of $980.85. How many pounds of type A coffee were used?

Answer 1

39 pounds of type A coffee were used.

Explanation:

Given: Cost of type A coffee is $4.15 per pound and cost of type B coffee is $5.25 per pound. Also, blend used four times as many pounds of type B coffee as type A.

To find: How many pounds of type A coffee were used.

Let
`x` be the number of pounds of type A coffee and
`y` be the number of pounds of type B coffee.

Then, according to question,

`4.15x+5.25y=980.85` and
`y=4x`

Substituting
`y=4x` in
`4.15x+5.25y=980.85`, we get

`4.15x+5.25(4x)=980.85`

⇒
`4.15x+21x=980.85`

⇒
`25.15x=980.85`

⇒
`x=(980.85)/(25.15)`

⇒
`x=39`

Therefore, 39 pounds of type A coffee were used.