JEE Main 2026 · 4 Apr · Shift 2 · Mathematics Q3

MathematicsSingle correct+4 / -1Question 3 of 75

If the system of equations:
$x+y+z=5,\qquad x+2y+3z=9,\qquad x+3y+\lambda z=\mu$
has infinitely many solutions, then the value of $\lambda+\mu$ is:

Answer and worked solution

Official answer: B

Infinitely many solutions. The third equation must be $2(\text{eq}_2)-(\text{eq}_1)$ , which is $x+3y+5z=13$ .

So $\lambda=5$ , $\mu=13$ , and $\lambda+\mu=18$ .

(B)

Topics:Systems of linear equations

JEE Main 2026 · 4 Apr · Shift 2, Mathematics question 3