a herd of cows gives 4 litres of milk each day. But each cow gives one third of total milk each day. They give 24 litres of milk in 6 days. How many cows are in the herd?

[tex]\tt \dfrac{1}{3}\times 4=\dfrac{4}{3}~L\\\\4\div \dfrac{4}{3}=\boxed{\bold{3~cows}}[/tex]