PSLE Andy and Ryan have the same total number of coins. Andy has a number of fifty-cent coins and 44 ten-cent coins. The total mass of his coins is 0.494 kg. Ryan has a number of fifty-cent coins and 74 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 1.5 g heavier than each ten-cent coin. What is the total mass of Ryan's coins in kg?
(a)
Both boys have the same number of coins. Since Ryan has more ten-cent coins than Andy, it means that Ryan has less fifty-cent coins than Andy. So Ryan has less money.
Difference in the number of ten-cent coins.
= 74 - 44
= 30
Difference in the value of 1 ten-cent coin and 1 fifty-cent coin
= 50 - 10
= 40¢
Amount that Ryan had less than Andy
= 30 x 40
= 1200¢
= $12
(b)
Difference in the mass between 30 ten-cent coins and 30 fifty-cent coins
= 30 x 1.5
= 45 g
= 0.045 kg
Total mass of Ryan's coins
= 0.494 - 0.045
= 0.449 kg
Answer(s): (a) Andy, $12; (b) 0.449 kg