Answer:
18 pounds
Explanation:
Quantity of Rift valley blend mixed = 90 pounds
Quantity of Arabian Mocha blend = 27 pounds
Mixture proportion of Rift valley blend : Arabian Mocha blend
= 90 : 27
= 10 : 3
This implies that for every 10 pounds of Rift Valley blend, we mix 3 pounds of Arabian Mocha.
So since the proportion is constant for the secret blend the let the unknown quantity of Arabian Mocha be "x" while the Rift Valley quantity be 60 pounds
Using constant proportion
10 :3 is equivalent to 60: x
Using the law of ratio, we have
3/10 = x/60
Cross multiplying both sides, we have:
10x =180
Dividing both sides by 10, we have:
x = 180/10
x = 18 pounds
So the quantity of Arabia Mocha to be used is 18 pounds.