Answer:
Step-by-step explanation:
First he has to decide on a pair of pants and he has 4 different choices.
For each of those choices he has a choice of 7 different shirts, so that gives him 4 times 7 = 28 different pant/shirt combinations. (I hope none of the pants are striped and none of the shirts have polka-dots).
For each those 28 possibilities, he has 5 different ties he could select, so altogether he has 28 times 5 = 140 different outfits, and some of them may be acceptable to wear in public.
It is simply , 4*5*7=140 ways.
