PSLE Wesley and Tom have the same total number of coins. Wesley has a number of fifty-cent coins and 56 five-cent coins. The total mass of his coins is 0.448 kg. Tom has a number of fifty-cent coins and 76 five-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 3.4 g heavier than each five-cent coin. What is the total mass of Tom's coins in kg?
(a)
Both boys have the same number of coins. Since Tom has more five-cent coins than Wesley, it means that Tom has less fifty-cent coins than Wesley. So Tom has less money.
Difference in the number of five-cent coins.
= 76 - 56
= 20
Difference in the value of 1 five-cent coin and 1 fifty-cent coin
= 50 - 5
= 45¢
Amount that Tom had less than Wesley
= 20 x 45
= 900¢
= $9
(b)
Difference in the mass between 20 five-cent coins and 20 fifty-cent coins
= 20 x 3.4
= 68 g
= 0.068 kg
Total mass of Tom's coins
= 0.448 - 0.068
= 0.38 kg
Answer(s): (a) Wesley, $9; (b) 0.38 kg