Andrea poured 6 litres of 10% cream into 3 litres of 15% cream. What is the percentage of cream in the final mixture?
final misture is 9 liters
inputs
.10 (6) and .15 (3)
.10(6) + .15(3) = x ( 9)
(.6 + .45 )/9 = x = .116666 or 11 2/3 %