Question

.
2) A box contains 20 balls bearing numbers 1, 2, 3, 4,
...., 20. A ball is drawn at random from the box. What
is the probability that the number on the ball is
(i) an odd number (ii) divisible by 2 or 3
(iii) prime number (iv) not divisible by 10.​

Answer 1

i) p(getting an odd no.)=13/20

ii)p(getting a no divisible by 2,3)=3/20

iii)p(getting a prime no.)=8/20=4/10=2/5

iv)p(a no. not divisible by 10)=18/20=9/10