There are 15% as many brown balls as white balls in Anna's collection of balls. The number of gold balls is 40% fewer than the number of white balls. There are 531 more gold balls than brown balls.

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

Brown	White	Gold
3x1	20x1
	5x4	3x4
3 u	20 u	12 u

(a)
15% = ¹⁵₁₀₀ = ³₂₀

100% - 40% = 60%
60% = ⁶⁰₁₀₀ = ³₅

The number of white balls is the repeated identity. Make the number of white balls the same.  LCM of 20 and 5 is 20.

Number of more gold balls than brown balls
= 12 u - 3 u
= 9 u

9 u = 531

1 u = 531 ÷ 9 = 59

Total number of balls in the collection
= 3 u + 20 u + 12 u 
= 35 u
= 35 x 59
= 2065

(b)
Percentage of the number of white balls as compared to the number of gold balls
= ⁵₃ x 100%
= ⁵⁰⁰₃ %
= 166²₃ %

Answer(s): (a) 2065; (b) 166²₃ %