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

Answer:

(a)

$P=0.7N+2.2$

(b)

the price of 50 cloud markers is $37.2

Step-by-step 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

$m=\frac{P_2-P_1}{N_2-N_1}$

now, we can plug values

$m=\frac{31.60-12.70}{42-15}$

$m=0.7$

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

$P=0.7\times 50+2.2$

$P=37.2$

So,

the price of 50 cloud markers is $37.2