Many of you not familiar with the sign(1). In above question sign (!) is called fictorial sign. The symbol (!) is like a exclamation mark! This symbol (!) in Mathematics means factorial. Simply it can be solve as 3! = 3 x 2 x 1 =6 and if 5! Then its solution is 5 x 4 x 3 x 2 x 1 = 120.

This is BODMAS/ PEMDAS related question and there is a problem in BODMAS or PEMDAS that factorial sign is not covered in it. So the question arrise where (which order) we should solve the fictorials in BODMAS. For this read read our article

Now let us we solve the question.
-2 + 3! -1 Solve the fictorial sign
(i.e 3!= 3.2.1=6)
= -2 + 6 - 1 Arrange the number +ve and -ve number
= 6 - 2 - 1
= 6 - 3
= 3