Answer:
Profit = $20
Step-by-step explanation:
It is given that a man bought a horse for $60 and sold it for $70. Then he bought it back for $80 and sold it for $90.
Total revenue = $70 + $90 = $160
Total expenditure = $60 + $80 = $140
The formula for profit is

Substitute $160 for revenue and $140 for expenditure in the above formula.


Therefore, he make $20 in the horse trading business.