Nicole has 30% as many pens as Kathy. Kathy has 110% as many pens as Eva. If Kathy gives 20 pens to Eva, both will then have an equal number of pens. Find the average number of pens the three of them have.

Nicole	Kathy	Eva
3x11	10x11
	11x10	10x10
33 u	110 u	100 u

30% = ³⁰₁₀₀ = ³₁₀
110% = ¹¹⁰₁₀₀= ¹¹₁₀

The number of pens that Nicole has is repeated.  Make the number of pens that Nicole has the same. LCM of 10 and 11 is 110.

	Kathy	Eva	Total
Before	110 u	100 u	210 u
Change	- 5 u	+ 5 u
After	105 u	105 u	210 u

Total number of pens that Kathy and Eva have
= 110 u + 100 u
= 210 u

After Kathy gives to Eva, both of them will have the same number of pens. 

The total number of pens that Kathy and Eva have remains unchanged.

Number of pens that each of them will have
= 210 u ÷ 2
= 105 u

Number of pens that Kathy gives to Eva
= 110 u - 105 u
= 5 u

5 u = 20

1 u = 20 ÷ 5 = 4

Total number of pens that three of them have
= 210 u + 33 u
= 243 u

Average number of pens that each of them have
= 243 u ÷ 3
= 81 u
= 81 x 4
= 324

Answer(s): 324