PSLE Owen and Will have the same total number of coins. Owen has a number of fifty-cent coins and 68 twenty-cent coins. The total mass of his coins is 0.534 kg. Will has a number of fifty-cent coins and 88 twenty-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 2.4 g heavier than each twenty-cent coin. What is the total mass of Will's coins in kg?
(a)
Both boys have the same number of coins. Since Will has more twenty-cent coins than Owen, it means that Will has less fifty-cent coins than Owen. So Will has less money.
Difference in the number of twenty-cent coins.
= 88 - 68
= 20
Difference in the value of 1 twenty-cent coin and 1 fifty-cent coin
= 50 - 20
= 30¢
Amount that Will had less than Owen
= 20 x 30
= 600¢
= $6
(b)
Difference in the mass between 20 twenty-cent coins and 20 fifty-cent coins
= 20 x 2.4
= 48 g
= 0.048 kg
Total mass of Will's coins
= 0.534 - 0.048
= 0.486 kg
Answer(s): (a) Owen, $6; (b) 0.486 kg