Wesley saved some 50-cent coins and $2 notes in his coin box. The total value of the 50-cent coins to the total value of the $2 notes he had was in the ratio 1 : 5. After $115 worth of 50-cent coins and an equal value of $2 notes were added to the coin box, the ratio of the total value of 50-cent coins to the total value of $2 notes became 6 : 7. How many of each type did Wesley have in the end?

1. 50-cent coins?
2. $2 notes?

	Value of 50-cent	Value of $2	Difference in  value
Before	1x1 = 1 u	5x1 = 5 u	4x1 = 4 u
Change	+ 115	+ 115
After	6x4 = 24 u	7x4 = 28 u	1x4 =  4 u

(a)
The difference in values between 50-cent and $2 remains unchanged. Make the difference in value the same. LCM of 4 and 1 is 4.

Increase in the value of 50-cent coins after more were added
= 24 u - 1 u
= 23 u

23 u = 115

1 u = 115 ÷ 23 = 5

Value of 50-cent coins in the end
= 24 u
= 24 x 5
= $120

100¢ = $1
50¢ = $0.50 

Number of 50-cent coins in the end
= 120 ÷ 0.50
= 240

(b)
Value of $2 notes in the end
= 28 u
= 28 x 5
= $140

Number of $2 notes in the end
= 140 ÷ 2
= 70

Answer(s): (a) 240; (b) 70