Mary has 25% as many pens as Usha. Usha has 130% as many pens as Nora. If Usha gives 42 pens to Nora, both will then have an equal number of pens. Find the average number of pens the three of them have.

Mary	Usha	Nora
1x13	4x13
	13x4	10x4
13 u	52 u	40 u

25% = ²⁵₁₀₀ = ¹₄
130% = ¹³⁰₁₀₀= ¹³₁₀

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

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

Total number of pens that Usha and Nora have
= 52 u + 40 u
= 92 u

After Usha gives to Nora, both of them will have the same number of pens. 

The total number of pens that Usha and Nora have remains unchanged.

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

Number of pens that Usha gives to Nora
= 52 u - 46 u
= 6 u

6 u = 42

1 u = 42 ÷ 6 = 7

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

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

Answer(s): 245