Question

A box contains 6 blue, 5 green and 4 red balls. If two balls are picked at random, then what is the probability that neither is blue?

• A. $\frac{10}{21}$
• B. $\frac{12}{35}$
• C. $\frac{3}{5}$
• D. $\frac{11}{21}$
• E. None of these

Answer 1

The correct option is B $\frac{12}{35}$

Total balls = 15
Not blue means green or red i.e any of (5+4)=9 balls
So probability $=\frac{{}^9{C}_2}{{}^{15}{C}_2}=\frac{12}{35}$