In how many ways can 5 boys and 3 girls stand in a row such that no two girls are together?

In how many ways can 7 boys and 5 girls be arranged in a row so that no two girls come together?

There are 7 boys and 3 girls in a class. In how many ways can they be arranged in a row such that no two girls are together?

In how many, ways can 5 boys and 5 girls be placed in a circle,so( that no two boys are side by side?

In how many ways can one post 3 letters in 5 post boxes?

In how many ways can a selection of 4 be made from 10 persons such that one particular person is always included

In how many ways can a selection of 4 be made from 10 persons such that one particular person is always excluded?

In how many ways can seven person be seat in a row of seats if two persons insist on sitting next to each other?

In how many ways can 10 scrips be arranged, so that the best and the worst do not come together?

How many tangents can you draw on a circle.

How many tangents can a circle have?