Question

hey (●’◡’●)ﾉ maths question please help ​

Answer 1

Answer:

Total balls =9+12=21

Probability of black balls =9/21

Answer 2

SOLUTION

TOTAL number of balls =9+12=21

now 1 ball can be drawn in (21C1) possible ways.

now the probability of drawing 1 black ball in random is

$\frac{9c1}{21c1} = \frac{9}{21} = \frac{3}{7}$

answer is =3/7