Solve the problem.
-A contractor mixes concrete from bags of pre-mix for small jobs. How many bags with 6% cement should he mix with 4 bags of 19.5% cement to produce a mix containing 9% cement?
A)23 bags
B)18 bags
C)14 bags
D)16 bags

Question

Quizplus · Accepted Answer

Let x be the number of bags with 6% cement that the contractor needs to mix.

The problem can be solved using the following equation:

0.06x + 0.195(4) = 0.09(x + 4)

Simplifying this equation yields:

0.06x + 0.78 = 0.09x + 0.36

0.03x = 0.42

x = 14

Therefore, the contractor needs to mix 14 bags with 6% cement to produce a mix containing 9% cement. Let the number of bags with 6% cement be x. 
We can set up the equation: 
0.06x + 4(0.195) = (x + 4)(0.09) 
Simplifying this equation gives us: 
0.06x + 0.78 = 0.09x + 0.36 
0.03x = 0.42 
x = 14

Therefore, the contractor should mix 14 bags with 6% cement to produce a mix containing 9% cement.

Solve the Problem. -A Contractor Mixes Concrete from Bags of Pre-Mix for Small