In how many ways 4 women draw water from 4 taps, if no tap remains unused?

Question

Philoid · Accepted Answer

1^st woman can draw water from anyone of the 4 taps.

Now, as, it is given, that, no tap should remain unused so, 2^nd woman can draw water from any of the remaining 3 taps.

Similarly, 3^rd women can draw water from any of the remaining 2 taps.

And, 4^th woman have to draw water from the remaining 1 tap.

As, the operations are dependent, so, total number of ways

= 4!

Alternative Approach:

The number of permutations of 4 objects taken 4 at a time is = ⁴P₄ = 4!.