Question

Five horses are in a race. A person selects 2 of the horses at random and bets on them. The probability that he selected the winning horse is

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

Answer 1

The correct option is D $\frac{2}{5}$

The man has selected the winning horse and one of the remaining four horses. This can be done in ${}_1^{4}C=4$ ways.
Total number of ways of selecting 2 horses from the 5 horses is ${}_2^{5}C=10$.
Hence, the required probability = $\frac{4}{10}=\frac{2}{5}$