Question

The price of a box of 15 cloud markers is $12.70. The price of a box of 42 cloud markers is $31.60. All prices are without tax, and the price of the packaging is the same for any size. How much would 50 cloud markers in a box cost? Write an equation which will tell the price P for the number N markers in the box.

Answer 1

(a)

`P=0.7N+2.2`

(b)

the price of 50 cloud markers is $37.2

Explanation:

(a)

Let's assume

price is P

number of markers is N

We are given

The price of a box of 15 cloud markers is $12.70

so,
`N_1=15,P_1=12.70`

The price of a box of 42 cloud markers is $31.60

so,
`N_2=42,P_2=31.60`

Firstly, we will find slope

`m=(P_2-P_1)/(N_2-N_1)`

now, we can plug values

`m=(31.60-12.70)/(42-15)`

`m=0.7`

now, we can use point slope form of line

`P-P_1=m(N-N_1)`

we can plug value

`P-12.70=0.7(N-15)`

now, we can solve for P

`P-12.70=0.7N-10.5`

add both sides by 12.70

`P-12.70+12.70=0.7N-10.5+12.70`

`P=0.7N+2.2`

(b)

now, we can plug N=50

`P=0.7* 50+2.2`

`P=37.2`

So,

the price of 50 cloud markers is $37.2