The number of five-cent coins in a coin box was ¹₄ the number of ten-cent coins. Flynn took out 18 ten-cent coins and exchanged them for five-cent coins. Then he put the money back into the coin box. The number of ten-cent coins became ⁵₈ the number of five-cent coins. How much money was there in the coin box?

	Make u the same (1)x4 = (3)	5-cent (1)	10-cent (2)
Before	4 u	1 u	4 u
Change	+ 144	+ 36	- 18
After	32 p	8 p	5 p

Value of 10-cent coins to be exchanged to 5-cent coins
= 18 x 10
= 180

Number of 5-cent coins to be exchanged from the 10-cent coins
= 180 ÷ 5
= 36

(3) = (2)
32 p - 144 = 5 p + 18
32 p - 5 p = 18 + 144
27 p = 162

1 p = 162 ÷ 27 = 6

Number of 5-cent coins in the end
= 8 p
= 8 p x 6
= 48

Value of 5-cent coins in the end
= 48 x 5
= 240¢

Number of 10-cent coins in the end
= 5 p
= 5 x 6
= 30

Value of 10-cent coins in the end
= 30 x 10
= 300¢

Total value of coins
= 240 + 300
= 540¢

$1 = 100¢
540¢ = $5.40 

Answer(s): $5.40