Question

Mary wants to buy a dress which costs $200 from the money she gets by working overtime. She has already saved up $50 for the dress. The following graph shows the money she will get by working extra hours.

How many extra hours does Mary need to work so that she can buy the dress of her choice?

Answer 1

The extra hours is 12 hours

Explanation:

We are given

She has already saved up $50 for the dress

and this is equation of line

so, y-intercept is 50

`b=50`

now, we can find slope

we can select any two points and then we can find slope

x1=0 , y1=50

x2=2 , y2=75

now, we can use formula

`m=(y_2-y_1)/(x_2-x_1)`

now, we can plug values

`m=(75-50)/(2-0)`

`m=(25)/(2)`

now, we can find equation

y=mx+b

`y=(25)/(2)x+50`

we are given y=200

so, we can set it to 200 and then we can solve for x

`200=(25)/(2)x+50`

`(25)/(2)x=150`

`25x=300`

`x=12`