Given the following expressions

1. - 5/8 + 3/5
2. 1/2 + square root 2
3. (Square root 5 ) x ( square root 5
4. 3 x ( square root 49)

Which expression result in a irrational number

1. 2 only
2. 3 only
3 . 1, 3 ,4
4. 2,3,4