Fiona has 25% as many coins as Usha. Usha has 130% as many coins as Zara. If Usha gives 30 coins to Zara, both will then have an equal number of coins. Find the average number of coins the three of them have.

Fiona	Usha	Zara
1x13	4x13
	13x4	10x4
13 u	52 u	40 u

25% = ²⁵₁₀₀ = ¹₄
130% = ¹³⁰₁₀₀= ¹³₁₀

The number of coins that Fiona has is repeated.  Make the number of coins that Fiona has the same. LCM of 4 and 13 is 52.

	Usha	Zara	Total
Before	52 u	40 u	92 u
Change	- 6 u	+ 6 u
After	46 u	46 u	92 u

Total number of coins that Usha and Zara have
= 52 u + 40 u
= 92 u

After Usha gives to Zara, both of them will have the same number of coins. 

The total number of coins that Usha and Zara have remains unchanged.

Number of coins that each of them will have
= 92 u ÷ 2
= 46 u

Number of coins that Usha gives to Zara
= 52 u - 46 u
= 6 u

6 u = 30

1 u = 30 ÷ 6 = 5

Total number of coins that three of them have
= 92 u + 13 u
= 105 u

Average number of coins that each of them have
= 105 u ÷ 3
= 35 u
= 35 x 5
= 175

Answer(s): 175