What is the mass for each type?

Question

One type of granola is 30% fruit and another type is 15% fruit. What mass of each type of granola should be mixed to make 600g of granola that is 21% fruit?

Answer 1

Let x represent the amount of the fruitier granola and y the less fruity. There is 0.3x and 0.15y amount of fruit in the mixture, which totals 600*0.21 or 126 g of fruit.

 

x + y = 600 threrefore y = 600 - x

0.3x + 0.15y = 126

0.3x + 0.15(600-x) = 126

0.3x + 90 - 0.15x = 126

0.15x + 90 = 126

0.15x = 36

x = 240

y = 600 - 240 = 360