There are 25% as many brown balls as silver balls in Pamela's collection of balls. The number of grey balls is 30% fewer than the number of silver balls. There are 504 more grey balls than brown balls.

1. Find the total number of balls in the collection.
2. What percentage are the number of silver balls as compared to the number of grey balls? Leave your answer as a mixed number in its simplest form.

Brown	Silver	Grey
1x5	4x5
	10x2	7x2
5 u	20 u	14 u

(a)
25% = ²⁵₁₀₀ = ¹₄

100% - 30% = 70%
70% = ⁷⁰₁₀₀ = ⁷₁₀

The number of silver balls is the repeated identity. Make the number of silver balls the same.  LCM of 4 and 10 is 20.

Number of more grey balls than brown balls
= 14 u - 5 u
= 9 u

9 u = 504

1 u = 504 ÷ 9 = 56

Total number of balls in the collection
= 5 u + 20 u + 14 u 
= 39 u
= 39 x 56
= 2184

(b)
Percentage of the number of silver balls as compared to the number of grey balls
= ¹⁰₇ x 100%
= ¹⁰⁰⁰₇ %
= 142⁶₇ %

Answer(s): (a) 2184; (b) 142⁶₇ %