Question 761621
He can choose from any of the 4 ties i.e. 4 ways to choose a tie.
He can choose from any of the 7 shirts i.e. 7 ways to choose a shirt.
He can choose from any of the 5 pants i.e. 5 ways to choose a pair of pants.

Any combination of tie, shirt and dress pants makes up ONE outfit.

So, number of possible outfits = number of possible combinations of shirt, tie and pants 

= 4 * 7 * 5 = 140 different outfits.


:)