Question

In a farm, on average every 6 cows produce 108 litres of milk per week. In five weeks the cows produced 2160 litres of milk. How many cows are in the farm?

Answer 1

2160L * 6cows/108L = 120 cows

including the units in your calculations makes it easy to keep track of what to multiply or divide, so that the unwanted units cancel out.

This is just a conversion problem (convert liters to cows), where 6cows/180L is the conversion factor.

Answer 2

12960/108

= 120

Answer 3

In a farm, on average every 6 cows produce 108 litres of milk per week. In five weeks the cows produced 2160 litres of milk. How many cows are in the farm?