How to i do i find the fixed cost or any number to to an equation similar to this when part of the equation information is left out

I know the break even equation is sales revenue - variable costs - fixed costs= break even point

Example

These data are for Patel Company.

Selling price per unit $5.00

Variable cost per unit $2.00

Number of units sold 50,000 units

Net income $40,000

Calculate the break-even point in number of units.

Possible answers

• 39,286 units
• 36,667 units
• 28,000 units
• 35,714 units