Question

An alloy weighing 30 lbs. is 11% tin. The alloy was made by mixing a 15% tin alloy and a 9% tin alloy. How many pounds of each alloy were used to make the 11% alloy?

Answer 1

Answer:

20 lbs of 9%

10 lbs of 15%

Step-by-step explanation:

x: 9%

y: 15%

x + y = 30

y = 30 - x

0.09x + 0.15y = 0.11(30)

0.09x + 0.15(30 - x) = 3.3

-0.06x = -1.2

x = 20

y = 10

y = 30 - x