Question

A jar contains 6 red marbles numbered 1 to 6 and 8 blue marbles numbered 1 to 8. A marble is drawn at random from the jar. Find the probability is marble is red or odd- numbered.

Answer 1

Solution:

Total 14 marbles (6 RED , 8 BLUE)

6 red marbles numbered 1 to 6

( 1,2,3,4,5,6)

8 blue marbles numbered 1 to 8

(1,2,3,4,5,6,7,8)

Event A : marble is red or odd- numbered.

There are 6 red marbles .

There are 7 marbles that are odd numbered. (1,3,5,1,3,5,7)

3 marbles are common in RED AND ODD Numbered

So , Event A contains 6 + 7 - 3 = 10 elements.

P(A) = Number of elements in A / Number of elements in sample space

= 10/14

=5/7

Required probability = 5/7 = 0.71428571428