There are a total of 310 pieces of 10-cent coins, 20-cent coins and 50-cent coins in Andy's piggy bank.
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 Andy's piggy bank?
(a)
Number of 10-cent coins
=
35 x 310
= 186
Number of 20-cent coins and 50-cent coins
= 310 - 186
= 124
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 = 124
1 u = 124 ÷ 4 = 31
Number of 50-cent coins
= 3 u
= 3 x 31
= 93
(b)
100¢ = $1
Total value of the 50-cent coins in Andy's piggy bank
= 93 x 50
= 4650¢
= $46.50
Answer(s): (a) 93; (b) $46.50