Question

Arun draws 3 balls at random from a basket which contains 4 red and 5 blue balls. What are the odds in favour of these being all blue?

• A. 5 : 42
• B. 5 : 37
• C. 4 : 43
• D. 4 : 50

Answer 1

The correct option is B 5 : 37

Probability of all three balls being blue = $\frac{{}^5{C}_3}{{}^9{C}_3}$ = $\frac{5}{52}$

Odds in favour of being blue =$\frac{5}{(42-5)}$= 5 : 37