Opal, Diana, Lynn and Xylia jointly contributed to the cost of a present for their schoolmate. Opal's contribution is
58 of the total contribution made by the four girls. The ratio of Xylia's contribution to the total of Diana's and Lynn's contribution is 2 : 1. What is the total contribution by the four girls if Diana's contribution is
13 of Lynn's contribution and the total amount contributed by Opal and Xylia is $448?
Opal |
Diana |
Lynn |
Xylia |
Total |
5x4 |
3x4 |
8x4 |
|
1x4
|
2x4 |
|
|
1x1 |
3x1 |
|
|
20 u |
1 u |
3 u |
8 u |
32 u |
Working backwards.
Total amount that Diana and Lynn had is the combined repeated identity.
LCM of 1 and 4 = 4
Total amount that Diana, Lynn and Xylia had is the next combined repeated identity.
LCM of 3 and 4 = 12
Total amount contributed by Opal and Xylia
= 20 u + 8 u
= 28 u
28 u = 448
1 u = 448 ÷ 28 = $16
Total contribution by the four girls
= 32 u
= 32 x 16
= $512
Answer(s): $512