Dana, Xuan, Pamela and Jen went to buy a souvenir for their father. They shared the cost equally among themselves. However, Jen forgot to bring her money. So, the other 3 girls paid for the souvenir first. Pamela paid ⁷₉ of the amount Dana and Xuan paid. Xuan paid $3 more than Dana. The next day, Jen returned $21 to Pamela and some money to Dana and Xuan. How much did Jen return to

1. Dana?
2. Xuan?

	Dana	Xuan	Pamela	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 + 3
Amounts that each girl paid for Jen first	- ?	- ?	- 21	+ 21 + ?
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 Pamela paid 
= 7 u - 4 u
= 3 u

3 u = 21

1 u = 21 ÷ 3 = 7

Total amount that Dana and Xuan paid at first
= 9 u
= 9 x 7
= $63

1 p + 1 p + 3 = 63
2 p = 63 - 3
2 p = 60

1 p = 60 ÷ 2 = 30

Amount that Jen needed to pay Dana
= 1 p - 4 u
= 30 - 4 x 7
= 30 - 28
= $2

(b)
Amount that Jen needed to pay Xuan
= (1 p + 3) - 4 u
= (30 + 3) - 4 x 7
= 33 - 28
= $5

Answer(s): (a) $2; (b) $5