Question

A bag contains tickets numbered 11, 12, 13, ..., 30. A ticket is taken out from the bag at random. Find the probability that the number on the drawn ticket
(i)is a multiple of 7
(ii)is greater than 15 and a multiple of 5.

Answer 1

SOLUTION :  

Given : Tickets marked with numbers from 11 to 30

Total number of outcomes = 20  

(i) Let E1 = Event of getting a multiple of 7

Numbers which is multiple of 7 are = 7,14,21,28

Number of outcome favourable to E1 = 4

Probability (E1) = Number of favourable outcomes / Total number of outcomes

P(E1) = 4/20 = 1/5

Hence, the required probability of getting a number which is multiple of 7 , P(E1) = 1/5 .

(ii) Let E2 = Event of getting a number which is greater than 15 and a multiple of 5..

Numbers which is greater than 15 and a multiple of 5  = 20, 25, 30

Number of outcome favourable to E2 = 3

Probability (E2) = Number of favourable outcomes / Total number of outcomes

P(E2) = 3/20  

Hence, the required probability of getting a number greater than 15 and a multiple of 5 , P(E2) = 3/20

HOPE THIS ANSWER WILL HELP YOU ...

Answer 2

So the right answer is i)1/5
ii)3/20