Rachel, Lucy, Joelle and Sarah went to buy a souvenir for their auntie. They shared the cost equally among themselves. However, Sarah forgot to bring her money. So, the other 3 girls paid for the souvenir first. Joelle paid
35 of the amount Rachel and Lucy paid. Lucy paid $3 more than Rachel. The next day, Sarah returned $7 to Joelle and some money to Rachel and Lucy. How much did Sarah return to
- Rachel?
- Lucy?
|
Rachel |
Lucy |
Joelle |
Sarah |
Total |
Comparing the amounts 3 girls paid first |
5 u
|
3 u
|
|
8 u
|
Comparing the amounts 2 girls paid first |
1 p
|
1 p + 3
|
|
|
|
Amounts that each girl paid for Sarah first |
- ? |
- ? |
- 7
|
+ 7 + ? |
|
Comparing the amounts each girl should pay |
1x2 = 2 u |
1x2 = 2 u |
1x2 = 2 u |
1x2 = 2 u |
4x2 = 8 u |
(a)
The total amount that the 4 girls paid is repeated. Make the total amount the same. LCM of 4 and 8 is 8.
Extra amount that Joelle paid
= 3 u - 2 u
= 1 u
1 u = 7
Total amount that Rachel and Lucy paid at first
= 5 u
= 5 x 7
= $35
1 p + 1 p + 3 = 35
2 p = 35 - 3
2 p = 32
1 p = 32 ÷ 2 = 16
Amount that Sarah needed to pay Rachel
= 1 p - 2 u
= 16 - 2 x 7
= 16 - 14
= $2
(b)
Amount that Sarah needed to pay Lucy
= (1 p + 3) - 2 u
= (16 + 3) - 2 x 7
= 19 - 14
= $5
Answer(s): (a) $2; (b) $5