There are a total of 290 pieces of 5-cent coins, 10-cent coins and 50-cent coins in John's coin box.
35 of these coins are 5-cent coins. The number of 50-cent coins is thrice the number of 10-cent coins.
- How many 50-cent coins are there?
- What is the total value of the 50-cent coins in John's coin box?
(a)
Number of 5-cent coins
=
35 x 290
= 174
Number of 10-cent coins and 50-cent coins
= 290 - 174
= 116
Number of 10-cent coins = 1 u
Number of 50-cent coins = 3 u
Number of 10-cent coins
= 1 u + 3 u
= 4 u
4 u = 116
1 u = 116 ÷ 4 = 29
Number of 50-cent coins
= 3 u
= 3 x 29
= 87
(b)
100¢ = $1
Total value of the 50-cent coins in John's coin box
= 87 x 50
= 4350¢
= $43.50
Answer(s): (a) 87; (b) $43.50