Emma, Mary, Zara and Nicole jointly contributed to the cost of a present for their sister. Emma's contribution is ⁶₇ of the total contribution made by the four girls. The ratio of Nicole's contribution to the total of Mary's and Zara's contribution is 3 : 2. What is the total contribution by the four girls if Mary's contribution is ¹₆ of Zara's contribution and the total amount contributed by Emma and Nicole is $4389?

Emma	Mary	Zara	Nicole	Total
6x35	1x35			7x35
	2x7		3x7
	1x2	6x2
210 u	2 u	12 u	21 u	245 u

Working backwards.

Total amount that Mary and Zara had is the combined repeated identity.
LCM of 2 and 7 = 14

Total amount that Mary, Zara and Nicole had is the next combined repeated identity.
LCM of 1 and 35 = 35 

Total amount contributed by Emma and Nicole
= 210 u + 21 u
= 231 u

231 u = 4389

2 u = 4389 ÷ 231 = $19

Total contribution by the four girls
= 245 u
= 245 x 19
= $4655

Answer(s): $4655