Question

Baking flour which costs $4.05/kg is made by combining bleached flour which costs

$5.75/kg with unbleached flour which costs $1.45/kg. Find the number of kg of bleached flour and unbleached flour required to make 17.2 kg of baking flour.

A) 11 kg of bleached flour, 6.2 kg of unbleached flour
B) 13.7 kg of bleached flour, 3.5 kg of unbleached flour
C) 12.7 kg of bleached flour, 4.5 kg of unbleached flour
D) 10.4 kg of bleached flour, 6.8 kg of unbleached flour

Answer 1

Answer: D) 10.4 kg of bleached flour, 6.8 kg of unbleached flour

Explanation:

First find the cost of making a kg of Baking flour.

Assume that x kgs of bleached flour and y kgs of unbleached flour make a kg of Baking flour.

The formulas would be;

x + y = 1

5.75x + 1.45y = 4.05

x = 1 - y

5.75 ( 1 - y) + 1.45y = 4.05

5.75 - 5.75y + 1.45y = 4.05

5.75 - 4.3y = 4.05

4.3y = 5.75 - 4.05

4.3y = 1.7

y = 1.7/4.3

y = 0.395 kg

x = 1 - 0.395

= 0.605kg

To make 1kg of Baking flour, 0.605kg of bleached flour and 0.395kg of unbleached flour is required.

To make 17.2kg of Baking flour;

Bleached flour = 0.605 * 17.2 = 10.4kg

Unbleached flour = 0.395 * 17.2 = 6.8 kg