There are 84 supermarkets in the FGH chain. All of them are either in the US or Canada. If there are 10 more FGH supermarkets in the US than in Canada, how many FGH supermarkets are there in the US?	Choose the correct choice from the following
A) 20	B) 31	C) 42	D) 47	E) 64

Rationale: "x + ( x - 10 ) = 84 - - > x = 47 . answer : d ."
Answer: D