Question

A jar contains 12 red marbles numbered 1 to 12 and 4 blue marbles numbered 1 to 4. A marble is drawn at random from the jar. Find the probability of the given event.
(a) The marble is red (b) The marble is odd-numbered (c) The marble is red or odd-numbered (d) The marble is blue and even-numbered

Answer 1

Total number of marbles in a jar = 12R +4B = 16 marbles

a) Prob( Marble is Red) = 12/16 = 3/4 =0.75

b)

The odd numbered Red marbles are = 1,3,5,7,9,11

The odd numbered blue marbles are = 1 ,3

Total odd numbered marbles = 6+2 =8

Prob( Odd numbered) = 8/16 =0.5

c)

There are total 12 red marbles and 2 odd numbered blue marbles , therefore the total numbers of red or odd numbered marles are = 14

Prob(Red or odd ) = 14/16 =7/8 =0.875

d)

There are only 2 marbles which are blue and even numbered , they are 2B, 4B

PRob. (Blue and even numbered) = 2/16 = 1/8 =0.125