Natalie, Shiyun, Jean and Tina jointly contributed to the cost of a present for their sister. Natalie's contribution is
34 of the total contribution made by the four girls. The ratio of Tina's contribution to the total of Shiyun's and Jean's contribution is 5 : 3. What is the total contribution by the four girls if Shiyun's contribution is
13 of Jean's contribution and the total amount contributed by Natalie and Tina is $1160?
Natalie |
Shiyun |
Jean |
Tina |
Total |
3x32 |
1x32 |
4x32 |
|
3x4
|
5x4 |
|
|
1x3 |
3x3 |
|
|
96 u |
3 u |
9 u |
20 u |
128 u |
Working backwards.
Total amount that Shiyun and Jean had is the combined repeated identity.
LCM of 3 and 4 = 12
Total amount that Shiyun, Jean and Tina had is the next combined repeated identity.
LCM of 1 and 32 = 32
Total amount contributed by Natalie and Tina
= 96 u + 20 u
= 116 u
116 u = 1160
3 u = 1160 ÷ 116 = $10
Total contribution by the four girls
= 128 u
= 128 x 10
= $1280
Answer(s): $1280