There are 20% as many white balls as blue balls in Sabrina's collection of balls. The number of grey balls is 30% fewer than the number of blue balls. There are 345 more grey balls than white balls.

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

White	Blue	Grey
1x2	5x2
	10x1	7x1
2 u	10 u	7 u

(a)
20% = ²⁰₁₀₀ = ¹₅

100% - 30% = 70%
70% = ⁷⁰₁₀₀ = ⁷₁₀

The number of blue balls is the repeated identity. Make the number of blue balls the same.  LCM of 5 and 10 is 10.

Number of more grey balls than white balls
= 7 u - 2 u
= 5 u

5 u = 345

1 u = 345 ÷ 5 = 69

Total number of balls in the collection
= 2 u + 10 u + 7 u 
= 19 u
= 19 x 69
= 1311

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

Answer(s): (a) 1311; (b) 142⁶₇ %