PSLE Tommy and Glen have the same total number of coins. Tommy has a number of fifty-cent coins and 55 ten-cent coins. The total mass of his coins is 1.006 kg. Glen has a number of fifty-cent coins and 115 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 3.7 g heavier than each ten-cent coin. What is the total mass of Glen's coins in kg?
(a)
Both boys have the same number of coins. Since Glen has more ten-cent coins than Tommy, it means that Glen has less fifty-cent coins than Tommy. So Glen has less money.
Difference in the number of ten-cent coins.
= 115 - 55
= 60
Difference in the value of 1 ten-cent coin and 1 fifty-cent coin
= 50 - 10
= 40¢
Amount that Glen had less than Tommy
= 60 x 40
= 2400¢
= $24
(b)
Difference in the mass between 60 ten-cent coins and 60 fifty-cent coins
= 60 x 3.7
= 222 g
= 0.222 kg
Total mass of Glen's coins
= 1.006 - 0.222
= 0.784 kg
Answer(s): (a) Tommy, $24; (b) 0.784 kg