Question

The typical family on the Planet Econ consumes 10 pizzas, 7 pairs of jeans, and 20 gallons of milk. In 2016, pizzas cost $10 each, jeans cost $40 per pair, and milk cost $3 per gallon. In 2017, the price of pizzas went down to $8 each, while the prices of jeans and milk remained the same. Between 2016 and 2017, a typical family's cost of living:

Answer 1

Answer:

decreased by 4.5%

Explanation:

A family consumes: 10 pizzas, 7 pairs of jeans, and 20 gallons of milk.

In 2016, pizzas cost $10 each, jeans cost $40 per pair, and milk cost $3 per gallon.

The family's total cost of living in 2016 is:

$C_{2016} = 10*\ 10 +7*\ 40 +20*\ 3\\C_{2016} = \ 440$

In 2017, pizzas cost $8 each, jeans cost $40 per pair, and milk cost $3 per gallon.

The family's total cost of living in 2017 is:

$C_{2017} = 10*\ 8 +7*\ 40 +20*\ 3\\C_{2016} = \ 420$

The change, in percentage, of a typical family's cost of living is:

$R=\frac{C_{2017}-C_{2016}}{C_{2016}} \\R=\frac{420-440}{440} \\R=0.045\ or\ 4.5\%$

The cost of living decreased by 4.5%