There are 20% as many yellow balls as white balls in Hilda's collection of balls. The number of red balls is 45% fewer than the number of white balls. There are 490 more red balls than yellow 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 red balls? Leave your answer as a mixed number in its simplest form.

Yellow	White	Red
1x4	5x4
	20x1	11x1
4 u	20 u	11 u

(a)
20% = ²⁰₁₀₀ = ¹₅

100% - 45% = 55%
55% = ⁵⁵₁₀₀ = ¹¹₂₀

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

Number of more red balls than yellow balls
= 11 u - 4 u
= 7 u

7 u = 490

1 u = 490 ÷ 7 = 70

Total number of balls in the collection
= 4 u + 20 u + 11 u 
= 35 u
= 35 x 70
= 2450

(b)
Percentage of the number of white balls as compared to the number of red balls
= ²⁰₁₁ x 100%
= ²⁰⁰⁰₁₁ %
= 181⁹₁₁ %

Answer(s): (a) 2450; (b) 181⁹₁₁ %