Question

In how ways 3 Maths, 5 Physics and 2 Chemistry books can be arranged on a shelf so that the books of same subject are not separated.

• A. ∠3 ∠3 ∠5 ∠2
• B. ∠3 ∠5 ∠2
• C. ∠10 /∠3 ∠5 ∠2
• D. None

Answer 1

Answer: (A)

∠3 ∠3 ∠5 ∠2

Answer 2

Consider Maths books as one unit, Physics books as one unit and Chemistry books as one unit then the 3 units can be arranged in ∠3 ways and the books in the units can be interchanged in ∠3 ∠5 ∠2 ways. Hence ∠3 ∠3 ∠5 ∠2.