Sarah, Gillian, Joelle and Vanessa went to buy a souvenir for their uncle. They shared the cost equally among themselves. However, Vanessa forgot to bring her money. So, the other 3 girls paid for the souvenir first. Joelle paid
79 of the amount Sarah and Gillian paid. Gillian paid $10 more than Sarah. The next day, Vanessa returned $36 to Joelle and some money to Sarah and Gillian. How much did Vanessa return to
- Sarah?
- Gillian?
|
Sarah |
Gillian |
Joelle |
Vanessa |
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 Vanessa 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 Joelle paid
= 7 u - 4 u
= 3 u
3 u = 36
1 u = 36 ÷ 3 = 12
Total amount that Sarah and Gillian 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 Vanessa needed to pay Sarah
= 1 p - 4 u
= 49 - 4 x 12
= 49 - 48
= $1
(b)
Amount that Vanessa needed to pay Gillian
= (1 p + 10) - 4 u
= (49 + 10) - 4 x 12
= 59 - 48
= $11
Answer(s): (a) $1; (b) $11