There are 25% more black marbles than silver marbles in a bag. After Japheth removed 40% of the black marbles and increased the number of silver marbles by 35%, there are now 96 fewer black marbles than silver marbles. Find the number of silver marbles at first.

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

Number of black marbles in percentage
= 100% + 25%
= 125%

125% = ¹²⁵₁₀₀ = ⁵₄

Number of black marbles that Japheth removed
= 40% x 5 u
= ⁴⁰₁₀₀ x 5 u 
= 2 u

Number of silver marbles that Japheth increased 
= 35% x 4 u
= ³⁵₁₀₀  x 4 u
= 1.4 u

Number of black marbles in the end
= 5 u - 2 u
= 3 u

Number of silver marbles in the end
= 4 u + 1.4 u
= 5.4 u

Number of fewer black marbles than silver marbles in the end
= 5.4 u - 3 u 
= 2.4 u 

2.4 u = 96

1 u = 96 ÷ 2.4 = 40

Number of silver marbles at first
= 4 u
= 4 x 40
= 160

Answer(s): 160