Esther, Abi, Zoe and Vanessa jointly contributed to the cost of a present for their classmate. Esther's contribution is
12 of the total contribution made by the four girls. The ratio of Vanessa's contribution to the total of Abi's and Zoe's contribution is 4 : 3. What is the total contribution by the four girls if Abi's contribution is
16 of Zoe's contribution and the total amount contributed by Esther and Vanessa is $385?
Esther |
Abi |
Zoe |
Vanessa |
Total |
1x49 |
1x49 |
2x49 |
|
3x7
|
4x7 |
|
|
1x3 |
6x3 |
|
|
49 u |
3 u |
18 u |
28 u |
98 u |
Working backwards.
Total amount that Abi and Zoe had is the combined repeated identity.
LCM of 3 and 7 = 21
Total amount that Abi, Zoe and Vanessa had is the next combined repeated identity.
LCM of 1 and 49 = 49
Total amount contributed by Esther and Vanessa
= 49 u + 28 u
= 77 u
77 u = 385
3 u = 385 ÷ 77 = $5
Total contribution by the four girls
= 98 u
= 98 x 5
= $490
Answer(s): $490