Riordan bought 25% more coins than David. Salik bought 20% fewer coins than Riordan. Riordan and David gave Salik some coins in the ratio 3 : 2. As a result, Salik had twice as much coins as before. Given that David had 9 more coins than Riordan in the end, how much coins did Salik receive?

	Riordan	David	Salik
	5x5	4x5
	5x5		4x5
Before	25 u	20 u	20 u
Change			+ (2 x 20 u) = + 40 u
	- 3x8 = - 24 u	- 2x8 = - 16 u	+ 5x8 =  + 40 u
After	1 u	4 u	60 u

100% + 25% = 125%
125% = ¹²⁵₁₀₀ = ⁵₄

100% - 20% = 80%
80% = ⁸⁰₁₀₀ = ⁴₅

The number of coins that Riordan had at first is the repeated identity.
LCM of 5 and 5 = 25

The change in the number of coins that Salik had is the repeated identity when Riordan and David gave to Salik.
LCM of 40 and 5 = 40

Number of coins that David had more than Riordan in the end
= 4 u - 1 u
= 3 u

3 u = 9
1 u = 9 ÷ 3 = 3

Number of coins that Salik received
= 24 u + 16 u
= 40 u
= 40 x 3
= 120

Answer(s): 120