I m unable to understand the question.

Please help me. What must be the answer????

USING TRIANGLE LAW OF VECTOR ADDITION:
RESULTANT of vectors having magnitude 3 and 1=√1²+3²+2(1)(3)cos90•
=>√10units and will be represented by a third side of triangle joined in opposite order.
The above will be added with vector having magnitude 5√2 units.
Therefore, Resultant={5√2+√10}  [ since the direction of two vectors are same, therefore the direction of resultant will also be 45• with x axis.]