Tank V contained 4 times as many guppies as Tank W. When 30% of the guppies in Tank V and 20% of the guppies in Tank W were transferred to Tank X, Tank X had 42 guppies, which was 50% more guppies than before. How many more guppies were there in Tank X than Tank W in the end?

	Tank V	Tank W	Tank X
Before	4 u	1 u	2x1.4 = 2.8 u
Change	- 1.2 u	- 0.2 u	+ 1x1.4 = + 1.4 u
After	2.8 u	0.8 u	3x1.4 = 4.2 u

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

Number of guppies that were transferred from Tank W to Tank X
= 20% x 1 u
= ²⁰₁₀₀ x 1 u
= 0.2 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
= 1.2 u + 0.2 u
= 1.4 u

4.2 u = 42

1 u = 42 ÷ 4.2 = 10

Number of more guppies in Tank X than Tank W
= 4.2 u - 0.8 u
= 3.4 u
= 3.4 x 10
= 34

Answer(s): 34