Carl and Oliver were given some allowances each. If Carl spent $13 each day and Oliver spent $26 each day, Carl would still have $645 left when Oliver spent all his allowance. If Carl spent $26 each day and Oliver spent $13 each day, Carl would still have $60 left when Oliver spent all his allowance.

1. How much allowance did Carl receive?
2. How much allowance did Oliver receive?

	Case 1		Case 2
	Carl	Oliver	Carl	Oliver
Before	1 u + 645	2 u	2 p + 60	1 p
Change	- 1 u	- 2 u	- 2 p	- 1 p
After	645	0	60	0

(a)
Simplify the ratio.
13 : 26 = 1 : 2

The allowance that Oliver had at first is the same for Case 1 and Case 2.

1 p = 2 u
2 p = 4 u

The allowance that Carl had at first is the same for Case 1 and Case 2.

4 u + 60 = 1 u + 645
4 u - 1 u = 645 - 60
3 u = 585

1 u = 585 ÷ 3 = 195

Allowance that Carl received
= 1 u + 645
= 195 + 645
= $840

(b)
Allowance that Oliver received
= 2 u
= 2 x 195
= $390

Answers: (a) $840; (b) $390