Q. If $N$ is the number of positive integral solution of $x_{1}x_{2}x_{3}x_{4} = 770$, then the value of $N$ is
A) 250
B) 252
C) 254
D) 256
Explanation
(d)
Now, 770=2.5.7.11
We can assigned 2 to $x_{1}$or$\ x_{2}$or $x_{3}$ or $x_{4}.$ That is 2 can be assigned in 4 ways.
Similarly each of 5, 7 or 11 can be assigned in 4 ways.
$\therefore$ Required number of ways $= 4^{4} = 256$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.