Question

A box contains numbers marked from 1 to 25, Bhavya draws out a number from the box. What
is the probability that he draws:
(a) an even number
(b) a composite number
(c) a prime number
(d) a number between 1 to 7​

Answer 1

Answer:

Step-by-step explanation:

SOLUTION

∵ The box contains numbers marked from 1 to 25

The total number of possible events = 25.

$\red\bigstar$ Probability of an event =  Number of favourable outcomes  

                                                Total number of outcomes

Then the  probability that she draws:-

(a) an even number is

The favourable outcomes are $\implies$ 2,4,6,8,10,12,14,16,18,20,22 and 24

Number of favourable outcomes is 12

$\bigstar$ So, the probability = $\frac{12}{25}$

(b) a composite number

The favourable outcomes are $\implies$

4,6,8,9,10,12,14,15,16,18,20,21,22,24,25

Number of favorable events = 15

$\bigstar$ Probability that the number chosen is a composite = $\frac{15}{25} = \frac{3}{5}$

(c) a prime number

Prime numbers from 1 to 25 are 2,3,5,7,11,13,17,19 and 23.

Number of favorable events = 9

$\bigstar$ Probability that the number chosen is a prime number = $\frac{9}{25}$

(d) a number between 1 to 7​

Favourable outcomes = 2,3,4,5,6

Number of favorable events = 5

$\bigstar$ Probability that the number chosen is a number between 1 to 7​ is = $\frac{5}{25} = \frac{1}{5}$