Question

24. 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?
(S.B.I. P.O., 2010)​

Answer 1

Answer:

probability of getting 2 red marbles is 1/3

Step-by-step explanation:

Total no.of marbles are: 12

no.of red balls : 4

probability of red balls :

:no.of favourable outcoms/total no.of possible outcomes

= 4/12

after cancellations

4/12=1/3

Therefore the answer is 1/3

1. HOPE IT WILL HELP U..

Answer 2

Answer:

The probability of both the marbles being red is  $\frac{1}{11}$

Step-by-step explanation:

Given the number of red marbles = 4

        the number of blue marbles = 5

      the number of green marbles = 3

=> Total number of marbles = 4 + 5 + 3 = 12

We know that 2 marbles are drawn out out of 12 = ¹²C₂

We need to find the probability of both the marbles being red

We know that probability = $\frac{FavourableOutcomes}{Total Outcomes}$

Since there are only 4 red marbles,

Both the marbles drawn out being red = ⁴C₂

Therefore, the probability = $\frac{^{4} C_{2}}{^{12} C_{2}}$

                                           = $\frac{6}{66}$

                                           = $\frac{1}{11}$

Therefore, the probability of both the marbles being red is  $\frac{1}{11}$