# Problem with decision making

• Nov 23rd 2008, 03:39 PM
fecoupefe
Problem with decision making
We have a problem.

Question is Aaron and 5 of his classmates are organizing a car wash to raise money.
They must purchase soap and sponges. The group expets to wash 100 cars. They plan to use 30 sponges.

Sponges
A - pack of 5 @ \$6 total
B - pack of 10 @8 total
C - pack of 15 @ \$10 total

Aaaon expects that if they purchase the least expensive sponges, they will need twice the number of sponges. Write a new estimate for the cost of the least expensive sponges.

Would that be \$12? -- or another answer. Tx for looking.
• Nov 23rd 2008, 03:55 PM
Steve_J
If I'm interpreting your question correctly...
If they're going to use 30 sponges, I think the costs would be as follows:

A - pack of 5 @ \$6 total, implies 30 sponges at \$36 (6 packs needed)
B - pack of 10 @8 total, implies 30 sponges at \$24 (3 pakcs needed)
C - pack of 15 @ \$10 total, implies 30 sponges at \$20 (2 packs needed)

So initially, it would seem that C is the best deal. But if using C sponges would require 60 sponges instead of 30, then the cost of using C-type sponges would double to \$40 (since you'd need 4 packs instead of 2), making B the best deal at \$24 in total.

Does that sound right?

- Steve J