Question

If the probability of a horse A winning a race is 1/4 and the probability of a horse B winning the same race is 1/5, then the probability that either of them will win the race is

• A. $\frac { 1 } { 20 }$
• B. $\frac { 9 } { 20 }$
• C. $\frac { 11 } { 20 }$
• D. $\frac { 19 } { 20 }$

Answer 1

Answer: (B)

$\frac { 9 } { 20 }$

Answer 2

$P ( A \cup B ) = P ( A ) + P ( B ) = \frac { 1 } { 4 } + \frac { 1 } { 5 } = \frac { 9 } { 20 }$

{Since events are mutually exclusive, so $P ( A \cap B ) = 0 \}$