At the faculty of Aerospace Engineering, 310 students study Random-processing methods, 232 students study Scramjet rocket engines and 112 students study them both. If every student in the faculty has to study one of the two subjects, how many students are there in the faculty of Aerospace Engineering?  Choose the correct choice:
A) 430	B) 432	C) 440	D) 442	E) 446

Rationale: "310 + 232 - 112 ( since 112 is counted twice ) = 430 a is the answer"
Answer: A