Question

there are 12 mathematics books and 8 science books on a shelf three of the science book are biology books a book is taken at random from the shelf find the probability that book is

Answer 1

Step-by-step explanation:

There are 11 books, 5 engineering books, 4 math books, and 2 physics books arranged in a shelf at random. What is the probability that books of each kind are all together?

This question should be in Mathematics section. Anyway, 11 books can be arranged in 11! ways. Now for your required event, if we want to stack books of same subjects together then there are 3! ways of arranging them subject wise.

For Example E,P,M or E,M,P or P,E,M or P,M,E or M,E,P or M,P,E.

Further 5 Engineering books can be arranged in 5! ways, 4 maths books in 4! ways and 2 physics books in 2! ways amongst themselves.

Like this way (E1,E2,E3,E4,E5) (P1,P2) (M1,M2,M3,M4) and similar other ways.

So total ways by which we can get the desired event are 2!*3!*4!*5!.

So probability becomes Probability = No of desired events / Total no. of event