There are a total of 280 pieces of 5-cent coins, 10-cent coins and 20-cent coins in Ryan's tin can.
37 of these coins are 5-cent coins. The number of 20-cent coins is four times the number of 10-cent coins.
- How many 20-cent coins are there?
- What is the total value of the 20-cent coins in Ryan's tin can?
(a)
Number of 5-cent coins
=
37 x 280
= 120
Number of 10-cent coins and 20-cent coins
= 280 - 120
= 160
Number of 10-cent coins = 1 u
Number of 20-cent coins = 4 u
Number of 10-cent coins
= 1 u + 4 u
= 5 u
5 u = 160
1 u = 160 ÷ 5 = 32
Number of 20-cent coins
= 4 u
= 4 x 32
= 128
(b)
100¢ = $1
Total value of the 20-cent coins in Ryan's tin can
= 128 x 20
= 2560¢
= $25.60
Answer(s): (a) 128; (b) $25.60