Question

There are 25 discs numbered 1 to 25. They are put in a closed box anx shaken thoroughly. A disc is drawn at random from the box. 
Find the probability that the number on the disc is :
(i) an odd number
(ii) divisible by 2 and 3 both.
(iii) a number less than 16.

Answer 1

(i) an odd number = {1,3,5,7,9,11,13,15,17,19,21,23,25}

    ∴ Probability of an odd number =${\displaystyle \frac{13}{25}}$

(ii) Divisible by 2 and 3 both = { 6,12,18,24 }

 Probability of the number divisible by 2 and 3 both = ${\displaystyle \frac{4}{25}}$

(iii) Probability a number less than 16 ${\displaystyle =\frac{15}{25}=\frac{3}{5}}$