There are 25% more pink cards than gold cards in a bag. After Ken removed 20% of the pink cards and increased the number of gold cards by 30%, there are now 108 fewer pink cards than gold cards. Find the number of gold cards at first.

	Pink	Gold
Before	5 u	4 u
Change	- 1 u	+ 1.2 u
After	4 u	5.2 u

Number of pink cards in percentage
= 100% + 25%
= 125%

125% = ¹²⁵₁₀₀ = ⁵₄

Number of pink cards that Ken removed
= 20% x 5 u
= ²⁰₁₀₀ x 5 u 
= 1 u

Number of gold cards that Ken increased 
= 30% x 4 u
= ³⁰₁₀₀  x 4 u
= 1.2 u

Number of pink cards in the end
= 5 u - 1 u
= 4 u

Number of gold cards in the end
= 4 u + 1.2 u
= 5.2 u

Number of fewer pink cards than gold cards in the end
= 5.2 u - 4 u 
= 1.2 u 

1.2 u = 108

1 u = 108 ÷ 1.2 = 90

Number of gold cards at first
= 4 u
= 4 x 90
= 360

Answer(s): 360