Answer:
39 pounds of type A coffee were used.
Step-by-step 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 be the number of pounds of type A coffee and be the number of pounds of type B coffee.
Then, according to question,
and
Substituting in , we get
⇒
⇒
⇒
⇒
Therefore, 39 pounds of type A coffee were used.