There are a total of 180 pieces of 5-cent coins, 20-cent coins and 50-cent coins in Tommy's tin can.
29 of these coins are 5-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 Tommy's tin can?
(a)
Number of 5-cent coins
=
29 x 180
= 40
Number of 20-cent coins and 50-cent coins
= 180 - 40
= 140
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 = 140
1 u = 140 ÷ 4 = 35
Number of 50-cent coins
= 3 u
= 3 x 35
= 105
(b)
100¢ = $1
Total value of the 50-cent coins in Tommy's tin can
= 105 x 50
= 5250¢
= $52.50
Answer(s): (a) 105; (b) $52.50