PSLE Pierre and Eric have the same total number of coins. Pierre has a number of fifty-cent coins and 42 twenty-cent coins. The total mass of his coins is 0.76 kg. Eric has a number of fifty-cent coins and 92 twenty-cent coins.
- Who has more money in coins? How much more? Give your answers in this format. (Eg Adam, $12)
- Each fifty-cent coin is 3.8 g heavier than each twenty-cent coin. What is the total mass of Eric's coins in kg?
(a)
Since Pierre has less twenty-cent coins than Eric but both had the same number of coins, Pierre had more money.
Both boys have the same number of coins. Since Pierre has less twenty-cent coins than Eric, it means that Pierre has more fifty-cent coins than Eric. So Pierre has more money.
Difference in the number of twenty-cent coins.
= 92 - 42
= 50
Difference in the value of 1 twenty-cent coin and 1 fifty-cent coin
= 50 - 20
= 30¢
Amount that Pierre had more than Eric
= 50 x 30
= 1500¢
= $15
(b)
Difference in the mass between 50 twenty-cent coins and 50 fifty-cent coins
= 50 x 3.8
= 190 g
= 0.19 kg
Total mass of Eric's coins
= 0.76 - 0.19
= 0.57 kg
Answer(s): (a) Pierre, $15; (b) 0.57 kg