Question

The odds of choosing one black ball from an urn are 7 to 13. what is the probability of getting a black ball?

Answer 1

Answer: $\dfrac{7}{20}$

Step-by-step explanation:

The odds for an event is basically the ratio of the favorable outcomes to the unfavorable outcomes.

Given : The odds of choosing one black ball from an urn are 7 to 13.

i.e. favorable outcomes for getting black ball = 7

i.e.  unfavorable outcomes for getting black ball = 13

Now , Total outcomes = favorable outcomes+  unfavorable outcomes

=7+13=20

Then, the probability of getting a black ball $=\dfrac{\text{Favorable outcomes}}{\text{Total outcomes}}$

$=\dfrac{7}{20}$

Hence, the required probability $=\dfrac{7}{20}$

Answer 2

I think the answer is 7/13.
Hope this helps.