A bag contains $$3$$ white, $$5$$ black, and $$2$$ red balls, all of the same shape and size. A ball is drawn from the bag without looking into it, find the probability that the ball is drawn is a black ball.
In a bag $$3$$ balls are white
$$2$$ balls are red
$$5$$ balls are black
Total number of balls $$=3+2+5=10$$
Number of possible outcomes of one black ball $$=10$$
and number of favourable outcomes of one black ball $$=5$$
We know that
$$P(E)=\dfrac{Number\ of\ favourable\ outcomes}{Number\ of\ all\ possible\ outcome}=\dfrac{5}{10}=\dfrac{1}{2}$$