Question

A bag contains 4 white, 5 black and 6 red balls. If a ball is drawn at random, then what is the probability that the drawn ball is either white or red

• A. $\frac { 4 } { 15 }$
• B. $\frac { 1 } { 2 }$
• C. $\frac { 2 } { 5 }$
• D. $\frac { 2 } { 3 }$

Answer 1

Answer: (D)

$\frac { 2 } { 3 }$

Answer 2

Probability for white ball $P ( W ) = \frac { 4 } { 15 }$

Probability for red ball $P ( R ) = \frac { 6 } { 15 }$

Probability (white or red ball) $= P ( W ) + P ( R )$

$= \frac { 4 } { 15 } + \frac { 6 } { 15 } = \frac { 10 } { 15 } = \frac { 2 } { 3 }$ .