# Select the correct option from the given alternatives : There are 2 shelves. One shelf has 5 Physics and 3 Biology books and the other has 4 Physics and 2 Biology books. The probability of drawing a - Mathematics and Statistics

MCQ

Select the correct option from the given alternatives :

There are 2 shelves. One shelf has 5 Physics and 3 Biology books and the other has 4 Physics and 2 Biology books. The probability of drawing a Physics book is

#### Options

• 9/14

• 31/48

• 9/38

• 1/2

#### Solution

31/48

Explanation:

Let event S1: First shelve is selected.

event S2: Second shelve is selected.

event P: Drawing a physics book.

∴ P(S1) = 1/2 and P(S2) = 1/2

First shelve has 5 physics and 3 biology books, i.e., total of 8 books.

∴ "P"("P"/"S"_1) = (""^5"C"_1)/(""^8"C"_1) = 5/8

Similarly, "P"("P"/"S"_2) = (""^4"C"_1)/(""^6"C"_1) = 4/6 = 2/3

∴ P(P) = "P"("S"_1)*"P"("P"/"S"_1) + "P"("S"_2)*"P"("P"/"S"_2)

= 1/2 xx 5/8 + 1/2 xx 2/3

= 31/48

Concept: Concept of Probability
Is there an error in this question or solution?

#### APPEARS IN

Balbharati Mathematics and Statistics 1 (Arts and Science) 11th Standard Maharashtra State Board
Chapter 9 Probability
Miscellaneous Exercise 9 | Q I. (5) | Page 213