Hazel, Zara, Lynn and Cathy went to buy a present for their grandmother. They shared the cost equally among themselves. However, Cathy forgot to bring her money. So, the other 3 girls paid for the present first. Lynn paid ⁷₉ of the amount Hazel and Zara paid. Zara paid $10 more than Hazel. The next day, Cathy returned $36 to Lynn and some money to Hazel and Zara. How much did Cathy return to

1. Hazel?
2. Zara?

	Hazel	Zara	Lynn	Cathy	Total
Comparing the amounts 3 girls paid first	9 u		7 u		16 u
Comparing the amounts 2 girls paid first	1 p	1 p + 10
Amounts that each girl paid for Cathy first	- ?	- ?	- 36	+ 36 + ?
Comparing the amounts each girl should pay	1x4 = 4 u	1x4 = 4 u	1x4 = 4 u	1x4 = 4 u	4x4 = 16 u

(a)
The total amount that the 4 girls paid is repeated. Make the total amount the same.  LCM of 4 and 16 is 16.

Extra amount that Lynn paid 
= 7 u - 4 u
= 3 u

3 u = 36

1 u = 36 ÷ 3 = 12

Total amount that Hazel and Zara paid at first
= 9 u
= 9 x 12
= $108

1 p + 1 p + 10 = 108
2 p = 108 - 10
2 p = 98

1 p = 98 ÷ 2 = 49

Amount that Cathy needed to pay Hazel
= 1 p - 4 u
= 49 - 4 x 12
= 49 - 48
= $1

(b)
Amount that Cathy needed to pay Zara
= (1 p + 10) - 4 u
= (49 + 10) - 4 x 12
= 59 - 48
= $11

Answer(s): (a) $1; (b) $11