Question

Why is the answer C?

Answer 1

Let's find the cost per pound (because we are given average of cost per pound) of the 10 pound bag and 25 pound bag:

`(80)/(10) = 8`

`(150)/(25) = 6`

Since the average of the three bags is 6, we can set up an equation, where x is the cost per pound for the 50 pound bag:

`(8+6+x)/(3) = 6`

Solve:

`14+x=18`

`x = 4`

Now, we have the cost per pound for the 50 pound bag, so let's multiply:

`50*4 = 200`

All in all, the 50 lbs bag cost $200.

Answer 2

Total pounds bought = 10 + 25 + 50 = 85 pounds

Given that the mean of all the flour is $6.

Total cost = 85 x 6 = $510

$510 - $80 - $150 = 280

Therefore the 50 pound flour cost $280

Answer: (C) : $280