Kathy has 25% as many erasers as Erika. Erika has 130% as many erasers as Min. If Erika gives 42 erasers to Min, both will then have an equal number of erasers. Find the average number of erasers the three of them have.

Kathy	Erika	Min
1x13	4x13
	13x4	10x4
13 u	52 u	40 u

25% = ²⁵₁₀₀ = ¹₄
130% = ¹³⁰₁₀₀= ¹³₁₀

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

	Erika	Min	Total
Before	52 u	40 u	92 u
Change	- 6 u	+ 6 u
After	46 u	46 u	92 u

Total number of erasers that Erika and Min have
= 52 u + 40 u
= 92 u

After Erika gives to Min, both of them will have the same number of erasers. 

The total number of erasers that Erika and Min have remains unchanged.

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

Number of erasers that Erika gives to Min
= 52 u - 46 u
= 6 u

6 u = 42

1 u = 42 ÷ 6 = 7

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

Average number of erasers that each of them have
= 105 u ÷ 3
= 35 u
= 35 x 7
= 245

Answer(s): 245