There are a total of 380 pieces of 10-cent coins, 20-cent coins and 50-cent coins in Xavier's tin can.
45 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 Xavier's tin can?
(a)
Number of 10-cent coins
=
45 x 380
= 304
Number of 20-cent coins and 50-cent coins
= 380 - 304
= 76
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 = 76
1 u = 76 ÷ 4 = 19
Number of 50-cent coins
= 3 u
= 3 x 19
= 57
(b)
100¢ = $1
Total value of the 50-cent coins in Xavier's tin can
= 57 x 50
= 2850¢
= $28.50
Answer(s): (a) 57; (b) $28.50