Mr tan bought x numbers of calculators for $1800. He then sold them at a fixed price of $30 each.

(A) Find the amount of money he gained in terms x if he sold all of them.
(B) If x = 75, find how much money he had gained.

1 answer

(A) To find the amount of money Mr. Tan gained in terms of x, we need to calculate the profit made from selling x calculators.

Cost price per calculator = $1800 / x
Selling price per calculator = $30

Profit per calculator = Selling price - Cost price
Profit per calculator = $30 - ($1800 / x)
Profit per calculator = $30 - ($1800 / x)

Total profit = Number of calculators sold * Profit per calculator
Total profit = x * ($30 - ($1800 / x))
Total profit = $30x - $1800

Therefore, the amount of money Mr. Tan gained in terms of x is $30x - $1800.

(B) If x = 75, we can substitute x into the equation we found in part (A) to find the total profit with 75 calculators sold.

Total profit = $30(75) - $1800
Total profit = $2250 - $1800
Total profit = $450

Therefore, when Mr. Tan sold 75 calculators, he gained $450.