Cost of Notepads based off certain number of notepads

Question

It costs $d$ dollars for $n$ notepads. At this rate, what is the cost of $n+750$ notepads, in dollars?

Answer 1

$n$ notepads cost $d$ dollars. That gives an average price of $\frac{d}{n}$ dollars per notepad. Thus if you have $n + 750$ notepads, the total cost in dollars is: $$(n+750)\frac{d}{n} = d + \frac{750d}{n}$$