Which is the better buy? Justify each
answer.
a) 6.2 L of gas for $5.39 or 8.5 L of gas
for $7.31
b) 5 candles for $3.00 or 12 candles for
$5.99
c) 2 kg of grass seed for $1.38 or 5 kg
of grass seed for $2.79
divide the price by the number of items to find the best unit cost
To determine the better buy in each scenario, we need to calculate the cost per unit for each option.
a) 6.2 L of gas for $5.39 or 8.5 L of gas for $7.31:
To calculate the cost per liter of gas, divide the total cost by the number of liters.
For option (a): $5.39 / 6.2 L = $0.87 per liter.
For option (b): $7.31 / 8.5 L = $0.86 per liter.
Therefore, option (b) is the better buy as it has a lower cost per liter.
b) 5 candles for $3.00 or 12 candles for $5.99:
To calculate the cost per candle, divide the total cost by the number of candles.
For option (a): $3.00 / 5 candles = $0.60 per candle.
For option (b): $5.99 / 12 candles = $0.50 per candle.
Therefore, option (b) is the better buy as it has a lower cost per candle.
c) 2 kg of grass seed for $1.38 or 5 kg of grass seed for $2.79:
To calculate the cost per kilogram of grass seed, divide the total cost by the number of kilograms.
For option (a): $1.38 / 2 kg = $0.69 per kg.
For option (b): $2.79 / 5 kg = $0.56 per kg.
Therefore, option (b) is the better buy as it has a lower cost per kilogram of grass seed.
In summary:
a) The better buy is 8.5 L of gas for $7.31 as it has a lower cost per liter.
b) The better buy is 12 candles for $5.99 as it has a lower cost per candle.
c) The better buy is 5 kg of grass seed for $2.79 as it has a lower cost per kilogram.