There are a total of 140 pieces of 5-cent coins, 20-cent coins and 50-cent coins in Japheth's piggy bank.
25 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 Japheth's piggy bank?
(a)
Number of 5-cent coins
=
25 x 140
= 56
Number of 20-cent coins and 50-cent coins
= 140 - 56
= 84
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 = 84
1 u = 84 ÷ 4 = 21
Number of 50-cent coins
= 3 u
= 3 x 21
= 63
(b)
100¢ = $1
Total value of the 50-cent coins in Japheth's piggy bank
= 63 x 50
= 3150¢
= $31.50
Answer(s): (a) 63; (b) $31.50