Question

A farmer was counting his cows and chickens. He counted 13 heads and 36 legs. How many cows does he have?

Answer 1

Cows (C)→ 4 legs
Chickens (c) → 2 legs
C+c=13 |×4
4C+2c=36

4C+4c=52
4C+2c=36
--------------- (-)
2c=16
c=8 chickens

C=13-8
C=5 cows