In how many ways can the investor select the group of three companies from the executive files?

Question

an investor has decided to purchase in the stock of three companies :one engaged in aerospace activaties, one involved in energy development, and one involved in electronics. After some research, the account executive of a brokerage firm recommended that the investor stock from five aerospace companies, three energy companies, and four electronics companies .

Answer 1

Assuming the three are different:

 

(5)(3)(4) = ?