Question

Type A coffee costs Bill 4.30
per pound, and type B coffee costs 5.70
per pound. This month, Bill made 168
pounds of the blend, for a total cost of 855.40
. How many pounds of type B coffee did he use?

Answer 1

4.30A+5.70B=855.40
A+B=168

A=168-B
substitute

4.30(168-B)+5.70B=855.40
4.30*168-4.30B+5.70B=855.40
1.40B =855-4.30*168
1.40B=132.60
B=132.60/1.40= 94.7 pounds≈95 pouds