Question

If $5x+11y$ is a prime number for natural number values of x and y, then what is the minimum value of $x+y$

• A. $2$
• B. $3$
• C. $4$
• D. $5$

Answer 1

The correct option is D $5$

By trial and error $5x+11y$ is prime number for

$(x,y)=(2,3)$

$(x,y)=(3,2)$

$(x,y)=(4,1)$

minimum value of $x+y=5$

D is the cdorrect option