# aig math (Ms.Sue)

posted by on .

At the pet store ruth bought 5 rawhide bones and 3 dog collars.She gave the cashier 90\$ and received \$6 in chage.If a dog collar costs 3 times as much as a bone find the cost of one dog collar.

My answer is 63 am i right if not please show me why and how.

• aig math (Ms.Sue) - ,

Your answer is obviously wrong. She bought 3 collars. If she paid 63 for one collar -- then she would have paid 189 for three.

• aig math (Ms.Sue) - ,

• aig math (Ms.Sue) - ,

Let's check:

(3 * 21) + (5 * 7) = 98

Nope -- you're getting closer.

• aig math (Ms.Sue) - ,

is it 18.

• aig math (Ms.Sue) - ,

Let's check.

(3 * 18) + (5 * 6) = 84

Right!!!

• aig math (Ms.Sue) - ,

my mother dosen't under how you get 18 can you please explain.

• aig math (Ms.Sue) - ,

I don't know. I found the right answer by trial and error.

Lidia-- I'm not a math teacher -- so please don't include my name on your future posts.

• aig math (Ms.Sue) - ,

cost of bone --- x
cost of collar --- 3x

5 bones + 3 collars = 84
5x + 3(3x) = 84
14x = 84
x = 84/14 = 6

cost of bone = \$6
cost of collar = 3(6) = \$18

• aig math (Ms.Sue) - ,

Thanks, Reiny!