Peter, Flynn, Riordan and Neave paid a total of $231 for a gift. Neave paid ²₅ of what the rest paid. Peter paid 50% of what the rest paid. Flynn and Riordan paid an equal amount of money. How much did Riordan pay?

Peter	Flynn	Riordan	Neave	Total
5x3			2x3	7x3
1x7	2x7			3x7
	1	1
7 u	4 u	4 u	6 u	21 u

50%= ⁵⁰₁₀₀= ¹₂
Peter's share : Total share = 1 : 2

The total amount paid for the gift is repeated.  Make the total amount the same.  LCM of 7 and 3 is 21.

Amount that Flynn, Riordan and Neave paid = 14 u

Amount that Flynn and Riordan paid
= 14 u - 6 u
= 8 u

The amount that Flynn and Riordan each paid is the same.

Amount that Flynn and Riordan each paid
= 8 u ÷ 2
= 4 u

Cost of the gift = 21 u

21 u = 231

1 u = 231 ÷ 21 = 11

Amount that Riordan paid
= 4 u
= 4 x 11
= $44

Answer(s): $44