PSLE Eric and Flynn have the same total number of coins. Eric has a number of fifty-cent coins and 62 twenty-cent coins. The total mass of his coins is 0.337 kg. Flynn has a number of fifty-cent coins and 112 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 1.5 g heavier than each twenty-cent coin. What is the total mass of Flynn's coins in kg?
(a)
Both boys have the same number of coins. Since Flynn has more twenty-cent coins than Eric, it means that Flynn has less fifty-cent coins than Eric. So Flynn has less money.
Difference in the number of twenty-cent coins.
= 112 - 62
= 50
Difference in the value of 1 twenty-cent coin and 1 fifty-cent coin
= 50 - 20
= 30¢
Amount that Flynn had less than Eric
= 50 x 30
= 1500¢
= $15
(b)
Difference in the mass between 50 twenty-cent coins and 50 fifty-cent coins
= 50 x 1.5
= 75 g
= 0.075 kg
Total mass of Flynn's coins
= 0.337 - 0.075
= 0.262 kg
Answer(s): (a) Eric, $15; (b) 0.262 kg