PSLE Ian and Paul have the same total number of coins. Ian has a number of fifty-cent coins and 60 ten-cent coins. The total mass of his coins is 0.751 kg. Paul has a number of fifty-cent coins and 120 ten-cent coins.
- Who has less money in coins? How much less? Give your answers in this format. (Eg Adam, $12)
- Each fifty-cent coin is 1.6 g heavier than each ten-cent coin. What is the total mass of Paul's coins in kg?
(a)
Both boys have the same number of coins. Since Paul has more ten-cent coins than Ian, it means that Paul has less fifty-cent coins than Ian. So Paul has less money.
Difference in the number of ten-cent coins.
= 120 - 60
= 60
Difference in the value of 1 ten-cent coin and 1 fifty-cent coin
= 50 - 10
= 40¢
Amount that Paul had less than Ian
= 60 x 40
= 2400¢
= $24
(b)
Difference in the mass between 60 ten-cent coins and 60 fifty-cent coins
= 60 x 1.6
= 96 g
= 0.096 kg
Total mass of Paul's coins
= 0.751 - 0.096
= 0.655 kg
Answer(s): (a) Ian, $24; (b) 0.655 kg