1-There-are-60-tickets-in-a-bag-numbered-1-through-60-If-a-ticket-is-picked-at-random-find-the-probability-that-the-number-is-divisible-by-3-or-4-

Question Number 27235 by das47955@mail.com last updated on 03/Jan/18

(1) There are 60 tickets in a bag

numbered 1 through 60 . If a ticket

is picked at random, find the

probability that the number is

divisible by 3 or 4 ?

Answered by Rasheed.Sindhi last updated on 03/Jan/18

Let A is the set of tickets numbered

by multiple of 3

n (A) = 60 / 3 = 20

and B is the set of tickets numbered

by multiple of 4

n (B) = 60 / 4 = 15

∴ A \cap B is the set of tickets numbered

by multiple of 12

n (A \cap B) = 60 / 12 = 5

∴ A \cup B is the set of the tickets

numbered by multiples of 3 or 4

n (A \cup B) = n (A) + n (B) - n (A \cap B)

= 20 + 15 - 5 = 30

If U is theUniversal set (Set of all the

tickets numbered by 1 to 60)

n (U) = 60

Probability = \frac{n (A \cup B)}{n (U)}

Probability = \frac{30}{60} = \frac{1}{2}

Commented by das47955@mail.com last updated on 03/Jan/18

T {hank}^{'} s sir