Tank T contained 4 times as many guppies as Tank U. When 10% of the guppies in Tank T and 20% of the guppies in Tank U were transferred to Tank V, Tank V had 144 guppies, which was 20% more guppies than before. How many less guppies were there in Tank U than Tank T in the end?

	Tank T	Tank U	Tank V
Before	4 u	1 u	5x0.6 = 3 u
Change	- 0.4 u	- 0.2 u	+ 1x0.6 = + 0.6 u
After	3.6 u	0.8 u	6x0.6 = 3.6 u

Number of guppies that were transferred from Tank T to Tank V
= 10% x 4 u
= ¹⁰₁₀₀ x 4 u
= 0.4 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
= 0.4 u + 0.2 u
= 0.6 u

3.6 u = 144

1 u = 144 ÷ 3.6 = 40

Number of less guppies in Tank U than Tank T
= 3.6 u - 0.8 u
= 2.8 u
= 2.8 x 40
= 112

Answer(s): 112