Answer:

Group of 5 men,which is n

Committee of 1 man,which is r

Using Formula of Combination

nCr=n!/(n-r)! r!

5C1=5!/(5-1)! 1!

5C1=5!/4! 1!

5C1=5×4!/4! 1!,cancelled out 4!

5C1=5/1

5C1=5

Group of 4 women,which is n

Committee of 3 women,which is r

Using Formula of Combination

nCr=n!/(n-r)! r!

4C3=4!/(4-3)! 3!

4C3=4!/1! 3!

4C3=4×3!/1! 3!,cancelled out 3!

4C3=4/1

4C3=4

=Committee of 1 man × Committee of 3 women

=5×4

=20 ways

:))))