Tank V contained 4 times as many guppies as Tank W. When 20% of the guppies in Tank V and 10% of the guppies in Tank W were transferred to Tank X, Tank X had 108 guppies, which was 50% more guppies than before. How many less guppies were there in Tank W than Tank V in the end?

	Tank V	Tank W	Tank X
Before	4 u	1 u	2x0.9 = 1.8 u
Change	- 0.8 u	- 0.1 u	+ 1x0.9 = + 0.9 u
After	3.2 u	0.9 u	3x0.9 = 2.7 u

Number of guppies that were transferred from Tank V to Tank X
= 20% x 4 u
= ²⁰₁₀₀ x 4 u
= 0.8 u

Number of guppies that were transferred from Tank W to Tank X
= 10% x 1 u
= ¹⁰₁₀₀ x 1 u
= 0.1 u

50% = ⁵⁰₁₀₀ = ¹₂

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

Total number of guppies transferred from Tank V and Tank W into Tank X
= 0.8 u + 0.1 u
= 0.9 u

2.7 u = 108

1 u = 108 ÷ 2.7 = 40

Number of less guppies in Tank W than Tank V
= 3.2 u - 0.9 u
= 2.3 u
= 2.3 x 40
= 92

Answer(s): 92