Question

At a clown hat factory, a feather is attached to every fourth of a hat that is made, a spinner is put on every seventh of a hat. Out of every 30 hats how many hats would have both a spinner and a feather?

Answer 1

P(F) = (1/4)

P(S) = (1/7)

Answer 2

Where F is feather, S is spinner

Answer 3

Probability (F and S) = (1/4) x (1/7) = (1/28)

Answer 4

So out of 30 hats you would expect 30 x (1/28) = 1.07 hats to have both. However, you obviously only have whole hats, so round it down to a whole number. You expect 1 hat to have both.