Question

The amount of money that Charlie saves each week is directly proportional to the amount he earns. Last week Charlie saved $32 on his earnings of $512. At the same rate, how much will Charlie save this week on his earnings of $448?

Answer 1

if k is a constant of proportionality then we know from last week that
512= k ·32 so k=512/32=16;

This week
448= k · amount he saved
448=16· amount he saved
amount saved=448/16=28

Answer $28

Answer 2

$28.

Explanation:

Let y represent of saved money and x represent amount of earned money.

We have been given that the amount of money that Charlie saves each week is directly proportional to the amount he earns.

We know that two proportional quantities are in form
`y=kx`, where, k is constant of proportionality.

Substitute given values and solve for k:

`32=k*512`

`(32)/(512)=(k*512)/(512)`

`(1)/(16)=k`

To find amount of saved money, we will substitute
`k=(1)/(16)` and
`x=448` in our equation.

`y=(1)/(16)\cdot 448`

`y=28`

Therefore, Charlie saved $28 in the given week.