Question

John started working part time at a local pet store and earned $24 a day. Two days later

Jack started working part time at a local music store and earned $30 a day. After how

many days do they earn the same amount?

Answer 1

Answer:

They earn the same amount after 8 days.

Step-by-step explanation:

When both started working(the day Jack started, John had been working for 2 days earning $24 a day, so he already had 2*24 = $48). We started modeling from this day.

John:

He already had $48.

He would earn $24 per day.

So after n days, his amount would be:

$A_{Jo}(n) = 48 + 24n$

Jack:

He has nothing.

He would earn $30.

So after n days, his amount would be:

$A_{Ja}(n) = 30n$

After how many days do they earn the same amount?

After n days.

n is found when:

$A_{Jo}(n) = A_{Ja}(n)$

$48 + 24n = 30n$

$6n = 48$

$n = \frac{48}{6}$

$n = 8$

They earn the same amount after 8 days.