There are 25% more silver coins than white coins in a bag. After Bryan removed 40% of the silver coins and increased the number of white coins by 35%, there are now 240 fewer silver coins than white coins. Find the number of white coins at first.

	Silver	White
Before	5 u	4 u
Change	- 2 u	+ 1.4 u
After	3 u	5.4 u

Number of silver coins in percentage
= 100% + 25%
= 125%

125% = ¹²⁵₁₀₀ = ⁵₄

Number of silver coins that Bryan removed
= 40% x 5 u
= ⁴⁰₁₀₀ x 5 u 
= 2 u

Number of white coins that Bryan increased 
= 35% x 4 u
= ³⁵₁₀₀  x 4 u
= 1.4 u

Number of silver coins in the end
= 5 u - 2 u
= 3 u

Number of white coins in the end
= 4 u + 1.4 u
= 5.4 u

Number of fewer silver coins than white coins in the end
= 5.4 u - 3 u 
= 2.4 u 

2.4 u = 240

1 u = 240 ÷ 2.4 = 100

Number of white coins at first
= 4 u
= 4 x 100
= 400

Answer(s): 400