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?

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

i not know

step-by-step explanation:

b) 1/3 * 1/5

step-by-step explanation:

each smallest part is 1/15 since the written one is 1/5 and it's divided by 3 equal parts. (1/5 )/3 = 1/15 = 1/3 * 1/5