A farmer bought a number of pigs for $210. However, 5 of them died before he could sell the rest at a profit of $4 per pig. His total profit was $65. How many pigs did he originally buy?

Answer 1

Let n = number of pigs bought originally

P = original price of each pig

The 2 equations will then be

nP = 210

(n-5)(P+4) = 210+65 = 275

Substitute P = 210/n into the second equation to get

4n² - 85n - 1050 = 0 and the only positive answer from this quadratic is 30 or 30 original pigs!