Question

A coin is tossed 8 times. In how many ways can we obtain 4 heads and 4 tails?

Answer 1

A coin is tossed 8 times. All heads are identical and all tails are identical.
We can obtain 4 heads and 4 tails in `(8!)/(4!4!)`

= `(8 xx 7 xx 6 xx 5 xx 4!)/((4 xx 3 xx 2 xx 1)4!)`

= 2 × 7 × 5
= 70 ways

∴ In 70 different ways, we can obtain 4 heads and 4 tails