Q. Eleven books consisting of 5 Mathematics, 4 physics and 2 Chemistry are places on a shelf. The number of possible ways of arranging them on the assumption that the books of the same subject are all together, is
A) $4!2!$
B) $11!$
C) $5!4!3!2!$
D) None of these
Explanation
(c)
Since, the books consisting of 5 Mathematics, 4 physics, and 2 chemistry can be put together of the same subject is $5!4!2!$ ways
But these subject books can be arranged itself in 3! ways
$\therefore$ Required number of ways $= 5!4!3!2!$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.