PSLE Mark and Luis have the same total number of coins. Mark has a number of fifty-cent coins and 58 five-cent coins. The total mass of his coins is 0.882 kg. Luis has a number of fifty-cent coins and 118 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 3.6 g heavier than each five-cent coin. What is the total mass of Luis's coins in kg?
(a)
Both boys have the same number of coins. Since Luis has more five-cent coins than Mark, it means that Luis has less fifty-cent coins than Mark. So Luis has less money.
Difference in the number of five-cent coins.
= 118 - 58
= 60
Difference in the value of 1 five-cent coin and 1 fifty-cent coin
= 50 - 5
= 45¢
Amount that Luis had less than Mark
= 60 x 45
= 2700¢
= $27
(b)
Difference in the mass between 60 five-cent coins and 60 fifty-cent coins
= 60 x 3.6
= 216 g
= 0.216 kg
Total mass of Luis's coins
= 0.882 - 0.216
= 0.666 kg
Answer(s): (a) Mark, $27; (b) 0.666 kg