Maths problem

This week we began our online learning. For maths we have been solving
problems. We have had to use facts we know to help us. Here is one of my
problems I have solved.

Legs in a Barn

Harley counted the number of legs he saw in the barn. He told his
mum he saw 30 legs. If the animals that Harley saw were some
chickens (2 legs), some calves (4 legs), and some bees (6 legs). How
many of each animal could Harley have seen if he saw 30 legs.

Solve this problem using the best strategy.