Gadvillafloresidn
Answered

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A tea merchant wants to make 20 pounds of a blended tea costing $5.60 per pound. The blend is made using a $6.50-per-pound grade of tea and a $4.25-per-pound grade of tea. How many pounds of each grade of tea should be used?

Sagot :

Shinalcantaraidn
let x=the amount of tea @6.50
    y=the amount of tea @4.25
   20(5.6)=the total amount of the blended tea

6.50(x) + 4.25(y) = 20(5.6)
6.5x + 4.25y = 112  ---equation 1

you're given that when the two grade of tea is added you'll have total weight of 20lbs
x+y = 20  -----eq'n 2
from eqn 2:
x = 20 - y  ----eq'n 3
substitute eqn 3 to eqn 1
6.50(20-y) + 4.25y =112
130 - 6.5y + 4.25y = 112
-2.25y = -18
y = 8 pounds

substitute y=8 to eq'n 3
x = 20 - 8
x = 12 pounds