Tank T contained 2 times as many guppies as Tank U. When 50% of the guppies in Tank T and 20% of the guppies in Tank U were transferred to Tank V, Tank V had 72 guppies, which was 20% more guppies than before. How many more guppies were there in Tank V than Tank U in the end?

	Tank T	Tank U	Tank V
Before	2 u	1 u	5x1.2 = 6 u
Change	- 1 u	- 0.2 u	+ 1x1.2 = + 1.2 u
After	1 u	0.8 u	6x1.2 = 7.2 u

Number of guppies that were transferred from Tank T to Tank V
= 50% x 2 u
= ⁵⁰₁₀₀ x 2 u
= 1 u

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

20% = ²⁰₁₀₀ = ¹₅

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

Total number of guppies transferred from Tank T and Tank U into Tank V
= 1 u + 0.2 u
= 1.2 u

7.2 u = 72

1 u = 72 ÷ 7.2 = 10

Number of more guppies in Tank V than Tank U
= 7.2 u - 0.8 u
= 6.4 u
= 6.4 x 10
= 64

Answer(s): 64