The cost, in taka, of manufacturing x microwaves is 6000+300x taka. The amount received when selling these x microwaves is 700x taka. What is the least number of microwaves that must be manufactured and sold so that the net profit is tk.2,400?

The cost, in taka, of manufacturing x microwaves is 6000+300x taka. The amount received when selling these x microwaves is 700x taka. What is the least number of microwaves that must be manufactured and sold so that the net profit is tk.2,400?

A 15

B 17

C 19

D 21

Solution

Correct Answer: Option D

700x-600-300x=2400

or, 400x-6000=2400

or, 400x=8400

or, x=8400/400

or, x= 21