Tank U contained 4 times as many guppies as Tank V. When 40% of the guppies in Tank U and 40% of the guppies in Tank V were transferred to Tank W, Tank W had 300 guppies, which was 25% more guppies than before. How many less guppies were there in Tank V than Tank U in the end?

	Tank U	Tank V	Tank W
Before	4 u	1 u	4x2 = 8 u
Change	- 1.6 u	- 0.4 u	+ 1x2 = + 2 u
After	2.4 u	0.6 u	5x2 = 10 u

Number of guppies that were transferred from Tank U to Tank W
= 40% x 4 u
= ⁴⁰₁₀₀ x 4 u
= 1.6 u

Number of guppies that were transferred from Tank V to Tank W
= 40% x 1 u
= ⁴⁰₁₀₀ x 1 u
= 0.4 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
= 1.6 u + 0.4 u
= 2 u

10 u = 300

1 u = 300 ÷ 10 = 30

Number of less guppies in Tank V than Tank U
= 2.4 u - 0.6 u
= 1.8 u
= 1.8 x 30
= 54

Answer(s): 54