A basket contains 4 red, 5 blue and 3 green marbles. If 2 marbles are drawn at random from the basket, What is the probability that both are red ?
A. $$\frac{{3}}{{7}}$$
B. $$\frac{{1}}{{2}}$$
C. $$\frac{{1}}{{11}}$$
D. $$\frac{{1}}{{6}}$$
E. None of these
Answer: Option C
Solution (By Examveda Team)
Total number of balls = (4 + 5 + 3) = 12Let E be the event of drawing 2 red balls.
Then, n (E) = $${}^4\mathop C\nolimits_2 = \frac{{4 \times 3}}{{2 \times 1}}$$ = 6
Also n (S) = $${}^{12}\mathop C\nolimits_2 = \frac{{12 \times 11}}{{2 \times 1}}$$ = 66
$$\therefore P(E) = \frac{{n(E)}}{{n(S)}} = \frac{6}{{66}} = \frac{1}{{11}}$$
This Question Belongs to Arithmetic Ability >> Probability
basket contains 4 red, 5 blue and 3 green marbles. If 3 marbles are drawn at random from the basket then the probability of all green marbles is