There are a total of 370 pieces of 10-cent coins, 20-cent coins and 50-cent coins in Owen's coin box.
35 of these coins are 10-cent coins. The number of 50-cent coins is thrice the number of 20-cent coins.
- How many 50-cent coins are there?
- What is the total value of the 50-cent coins in Owen's coin box?
(a)
Number of 10-cent coins
=
35 x 370
= 222
Number of 20-cent coins and 50-cent coins
= 370 - 222
= 148
Number of 20-cent coins = 1 u
Number of 50-cent coins = 3 u
Number of 20-cent coins
= 1 u + 3 u
= 4 u
4 u = 148
1 u = 148 ÷ 4 = 37
Number of 50-cent coins
= 3 u
= 3 x 37
= 111
(b)
100¢ = $1
Total value of the 50-cent coins in Owen's coin box
= 111 x 50
= 5550¢
= $55.50
Answer(s): (a) 111; (b) $55.50