Tank U contained 4 times as many guppies as Tank V. When 30% of the guppies in Tank U and 20% of the guppies in Tank V were transferred to Tank W, Tank W had 70 guppies, which was 25% more guppies than before. How many more guppies were there in Tank W than Tank V in the end?

	Tank U	Tank V	Tank W
Before	4 u	1 u	4x1.4 = 5.6 u
Change	- 1.2 u	- 0.2 u	+ 1x1.4 = + 1.4 u
After	2.8 u	0.8 u	5x1.4 = 7 u

Number of guppies that were transferred from Tank U to Tank W
= 30% x 4 u
= ³⁰₁₀₀ x 4 u
= 1.2 u

Number of guppies that were transferred from Tank V to Tank W
= 20% x 1 u
= ²⁰₁₀₀ x 1 u
= 0.2 u

25% = ²⁵₁₀₀ = ¹₄

Some guppies from Tank U and Tank V were transferred to Tank W.  The total number of guppies transferred from Tank U and Tank V into Tank W is the same.

Total number of guppies transferred from Tank U and Tank V into Tank W
= 1.2 u + 0.2 u
= 1.4 u

7 u = 70

1 u = 70 ÷ 7 = 10

Number of more guppies in Tank W than Tank V
= 7 u - 0.8 u
= 6.2 u
= 6.2 x 10
= 62

Answer(s): 62