There are 10% as many grey balls as brown balls in Hilda's collection of balls. The number of green balls is 40% fewer than the number of brown balls. There are 275 more green balls than grey balls.

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

Grey	Brown	Green
1x1	10x1
	5x2	3x2
1 u	10 u	6 u

(a)
10% = ¹⁰₁₀₀ = ¹₁₀

100% - 40% = 60%
60% = ⁶⁰₁₀₀ = ³₅

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

Number of more green balls than grey balls
= 6 u - 1 u
= 5 u

5 u = 275

1 u = 275 ÷ 5 = 55

Total number of balls in the collection
= 1 u + 10 u + 6 u 
= 17 u
= 17 x 55
= 935

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

Answer(s): (a) 935; (b) 166²₃ %