Question

A bag holds 11 beads. 7 are red, the rest are white. Two beads are taken at random from the bag. What is the proba polity that one bead of each colour is taken?

Answer 1

Probability that one bead of each colour is taken from $\bold{\frac{14}{55}}$.

Solution:

Given that  

Total number of Beds = 11

Number of red beds = 7

Number of white beds = 11 – 7 = 4

Two beads are taken at random from the bag.  Need to find the probability that one bead of each colour is taken.

$\text { Probability of getting red bed }=\frac{\text { number of red beds }}{\text { total number of beds }}=\frac{7}{11}$

$\text { Probability of getting a white after first one is red }=\frac{\text { number of white beds }}{( \text { total number of beds-1) } }=\frac{4}{10}$

So probability that one bead of each colour is taken = Probability of getting red bed multiplied by Probability of getting a white after first one is red  

$\Rightarrow \frac{7}{11} \times \frac{4}{10}=\frac{28}{110}=\frac{14}{55}$

Hence, required probability is $\frac{14}{55}$

Answer 2

Answer:

56/110=14/55

Step-by-step explanation:

you get 4 marks!