I cannot see the problem properly. Can the problem be solved step by step mathematically (numerically) instead of written explanation?

how do you solve for this problem?

Number theory question

Calculus for Business Economics

For the following story problems:1st) Define the variable(s) – there will be either 1 or 2 variables 2nd) Write an equation or system of equations3rd ) Solve and answer the questions using the correct units Mr. Baker owns and operates a company that manufactures calculators. In a single day it costs 2400ドル for operational costs plus 15ドル to build each calculator. The company sells the calculators for 39ドル each. How many calculators must the company sell in a single day in order to make a profit?