Kimberly, Elyse, Min and Opal jointly contributed to the cost of a present for their sister. Kimberly's contribution is ²₅ of the total contribution made by the four girls. The ratio of Opal's contribution to the total of Elyse's and Min's contribution is 5 : 4. What is the total contribution by the four girls if Elyse's contribution is ¹₄ of Min's contribution and the total amount contributed by Kimberly and Opal is $660?

Kimberly	Elyse	Min	Opal	Total
2x15	3x15			5x15
	4x5		5x5
	1x4	4x4
30 u	4 u	16 u	25 u	75 u

Working backwards.

Total amount that Elyse and Min had is the combined repeated identity.
LCM of 4 and 5 = 20

Total amount that Elyse, Min and Opal had is the next combined repeated identity.
LCM of 3 and 15 = 45 

Total amount contributed by Kimberly and Opal
= 30 u + 25 u
= 55 u

55 u = 660

4 u = 660 ÷ 55 = $12

Total contribution by the four girls
= 75 u
= 75 x 12
= $900

Answer(s): $900