If a=b and 1/c=b, then c=?

1. To write "SAS IDEAS" how many times you have to press in keyboard.
8
9
10
11

Ans: 10

2. If a=b and 1/c=b, then c=?
a
1/a
2a
a/b

Ans: 1/a

3. If 850+x+y-640=342, and if x=2y, then y=?
42
44
132
184

Ans: 44

4. Which is wrong?
999/13*25=1921.15
888/13*25=1707.7
777/13*26=1554
none of them

Ans: none of them

5. Which is Prime Number?
4
6
7
10

Ans: 7