PSLE Reggie and Andy have the same total number of coins. Reggie has a number of fifty-cent coins and 30 ten-cent coins. The total mass of his coins is 0.452 kg. Andy has a number of fifty-cent coins and 80 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 2.2 g heavier than each ten-cent coin. What is the total mass of Andy's coins in kg?
(a)
Both boys have the same number of coins. Since Andy has more ten-cent coins than Reggie, it means that Andy has less fifty-cent coins than Reggie. So Andy has less money.
Difference in the number of ten-cent coins.
= 80 - 30
= 50
Difference in the value of 1 ten-cent coin and 1 fifty-cent coin
= 50 - 10
= 40¢
Amount that Andy had less than Reggie
= 50 x 40
= 2000¢
= $20
(b)
Difference in the mass between 50 ten-cent coins and 50 fifty-cent coins
= 50 x 2.2
= 110 g
= 0.11 kg
Total mass of Andy's coins
= 0.452 - 0.11
= 0.342 kg
Answer(s): (a) Reggie, $20; (b) 0.342 kg