A student bought a box of calculators for $300. She gave 15 of them to the teacher and then sold the rest for $330, making a profit of $1.50 on each one. How many calculators were in the box at the start? What was the original price of each calculator?

Given :

A student bought a box of calculators for $300. She gave 15 of them to the teacher and then sold the rest for $330, making a profit of $1.50 on each one.

To Find :

How many calculators were in the box at the start? What was the original price of each calculator?

Solution :

Let, initial number of calculators are x and price of each calculator is p.

So, overall profit is equal to profit on each multiplied by remaining calculator.

( x - 15)( 1.50 ) = 330 - 300

x - 15 = 20

x = 35

Also, original price of each calculator is :

p = $300/35

p = $8.57

Hence, this is the required solution.

answer:   x = 3 + √11     and     x = 3 - √11

step-by-step explanation:

x² - 6x + 9 = 11

(x - 3)² = 11

x - 3 = ±√11

    x = 3 ± √11

x = 3 + √11     and     x = 3 - √11

the first one is x^2+2x+2

the second one is x^2+4

the last one is x^2-4x+8