UPSC Civil Services 2018 Prelims General Studies Paper II

Checking statement 1
x – y = 8
Both x and y must be positive for any value of x and y.
It is not true because negative values of x and y or positive x and negative y is also possible
Checking statement 2
If x is positive, y must be negative for any value of x and y.
It is alos not true because positive values of x and y are also possible.
Checking statement 3
If x is negative, y must be positive for any value of x and y.
Here if x is negative then only negative value of y is possible.
Hence, neithter 1 nor 2 nor 3