Numbers-14 (CAT-2006)

The number of solutions of the equation 2x+y=40 where both x and y are positive integers and x ≤ y is:

(1) 7                (2) 13                (3) 14              (4) 18                (5) 20

Solution follows here:

Solution:

It’s a straight forward question.

2x+y=40;        x ≤ y;

All possible solutions are:

x=1,y=38;

x=2,y=36;

and so on...

and so on..

x=13,y=14; (After this, for x=14, we get y=12 which is wrong as x should be less than y)

Total possible solutions are 13

Answer (2)