Linda, Sarah, Gillian and Jen went to buy a souvenir for their younger sister. They shared the cost equally among themselves. However, Jen forgot to bring her money. So, the other 3 girls paid for the souvenir first. Gillian paid ⁷₉ of the amount Linda and Sarah paid. Sarah paid $4 more than Linda. The next day, Jen returned $36 to Gillian and some money to Linda and Sarah. How much did Jen return to

1. Linda?
2. Sarah?

	Linda	Sarah	Gillian	Jen	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 + 4
Amounts that each girl paid for Jen 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 Gillian paid 
= 7 u - 4 u
= 3 u

3 u = 36

1 u = 36 ÷ 3 = 12

Total amount that Linda and Sarah paid at first
= 9 u
= 9 x 12
= $108

1 p + 1 p + 4 = 108
2 p = 108 - 4
2 p = 104

1 p = 104 ÷ 2 = 52

Amount that Jen needed to pay Linda
= 1 p - 4 u
= 52 - 4 x 12
= 52 - 48
= $4

(b)
Amount that Jen needed to pay Sarah
= (1 p + 4) - 4 u
= (52 + 4) - 4 x 12
= 56 - 48
= $8

Answer(s): (a) $4; (b) $8