A farmer bought a number of pigs for $138. However, 4 of them died before he could sell the rest at a profit of 8 per pig. His total profit was $128. How many pigs did he originally buy?

Answer 1

To answer this question, let us begin with the total profit, that is $128. We know that he sold the remaining pigs at a profit of $8 per pig so the number of pigs that he got a profit from, were 128/8, which is equal to 16. Now, we also know that 4 pigs died before he could sell the rest. Hence, the number of pigs he originally bought are 4+16, which is equal to 20.

Answer 2

He sold the remaining pigs at $8 profit each and earned a profit of $128.

128-8 = 120 (1 pig)

120-8 = 112 (2 pigs)

112- 8 = 104 (3 pigs)

you can continue until you get to 0

OR you can realize that repeated substraction is just division

Now 128/8 = 16

So the farmer sold 16 pigs. Adding on the 4 pigs that died we know the farmer originally purchased 20 pigs.