Question

A number from 1 to 21 is chosen at random. What is the probability of choosing (i)an prime number (ii) a multiple of 4​

Answer 1

Answer:

i) - $\frac{8}{21}$ ; ii) - $\frac{5}{21}$

Step-by-step explanation:

i) - Total number of outcomes = 21

No. of favourable outcomes ( 2,3,5,7,11,13,17,19 ) = 8

Therefore

Probability = Total no. of outcomes/number of favourable outcomes

⇒ $\frac{8}{21}$

ii) - Total number of outcomes = 21

No. of favourable outcomes ( 4,8,12,16,20 ) = 5

Therefore,

Probability = Total no. of outcomes/number of favourable outcomes

⇒ $\frac{5}{21}$

Answer 2

Answer:

Step-by-step explanation:

Probability = Total no. of outcomes/number of favourable outcomes

Therefore,

answers are,

8/21 and 5/21