Science > Mathematics > Statistics and Probability > Probability > Problems Based on Numbered Tickets
In the last article, we have studied problems on the throwing of dice. In this article, we shall study to solve problems to find probability involving numbered tickets.
Drawing Two or More Numbered tickets:
Example – 01:
Tickets numbered from 1 to 50 are mixed up together and then two tickets are drawn at random what is the probability that
Solution:
The sample space is S = {1, 2, 3, …….., 50}.
Two tickets are drawn at random.
Hence n(S) = 50C2 = 1225
a) both the tickets bear an even number
Let A be the event that both the tickets bear an even number
Favourable points are 2, 4, 6, 8, 10, … , 50
There are 25 favourable points
∴ n(A) = 25C2 = 300
By the definition P(A) = n(A)/n(S) = 300/1225 = 12/49
Therefore the probability that both the tickets bear an even number is 12/49
b) both the tickets bear an odd number
Let B be the event that both the tickets bear an odd number
Favourable points are 21, 3, 5, 7, ….., 49
There are 25 favourable points
∴ n(B) = 25C2 = 300
By the definition P(B) = n(B)/n(S) = 300/1225 = 12/49
Therefore the probability that both the tickets bear an odd number is 12/49
c) both the tickets bear a perfect square
Let C be the event that both the tickets bear a perfect square
Favourable points are 1, 4, 9, 16, 25, 36, 49
There are 7 favourable points
∴ n(C) = 7C2 = 21
By the definition P(C) = n(C)/n(S) = 21/1225 = 3/175
Therefore the probability that both the tickets bear a perfect square is 3/175
d) Both the tickets bear a number multiple of four (or divisible by four)
Let D be the event that both the tickets bear a number multiple of four
Favourable points are 4, 8, 12, 16, …., 48
There are 12 favourable points
∴ n(D) = 12C2 = 66
By the definition P(D) = n(D)/n(S) = 66/1225
Therefore the probability that both the tickets bear a number multiple of four is 66/1225
e) both the tickets bear a number multiple of three (or divisible by three)
Let E be the event that both the tickets bear a number multiple of three
Favourable points are 3, 6, 9, …., 48
There are 16 favourable points
∴ n(E) = 16C2 = 120
By the definition P(E) = n(E)/n(S) = 120/1225 = 24/245
Therefore the probability that both the tickets bear a number multiple of three is 24/245
f) both the tickets bear a number greater than 44
Let F be the event that both the tickets bear a number greater than 44
Favourable points are 45, 46, 47, 48, 49, 50
There are 6 favourable points
∴ n(F) = 6C2 = 15
By the definition P(F) = n(F)/n(S) = 15/1225 = 3/245
Therefore the probability that both the tickets bear a number greater than 44 is 3/245
g) both the tickets bear a number less than 11
Let G be the event that both the tickets bear a number less than 11
Favourable points are 1, 2, 3, ……, 10
There are 10 favourable points
∴ n(G) = 10C2 = 45
By the definition P(G) = n(G)/n(S) = 45/1225 = 9/245
Therefore the probability that both the tickets bear a number less than 11 is 9/245
h) both the tickets bear perfect square or number less than 10
Let H be the event that both the tickets bear perfect square or number less than 10
Favourable points are 1, 4, 9, 16, 25, 36, 49, 2, 3, 5, 6, 7, 8
There are 13 favourable points
∴ n(H) = 13C2 = 78
By the definition P(H) = n(H)/n(S) = 45/1225 = 9/245
Therefore the probability that both the tickets bear perfect square or a number less than 5 is 78/1225
i) both the tickets bear a prime number
Let J be the event that both the tickets bear a prime number
Favourable points are 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47
There are 15 favourable points
∴ n(J) = 15C2 = 105
By the definition P(J) = n(J)/n(S) = 105/1225 = 3/35
Therefore the probability that both the tickets bear a prime number is 3/35
j) both the tickets bear a prime number or a perfect square
Let K be the event that both the tickets bear a prime number or a perfect square
Favourable points are 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37,
41, 43, 47, 1, 4, 9, 16, 25, 36, 49
There are 22 favourable points
∴ n(K) = 22C2 = 231
By the definition P(K) = n(K)/n(S) = 231/1225 = 33/175
Therefore the probability that both the tickets bear a prime number or a perfect square is 33/175
both the tickets bear a number greater than 35 and an even number.
Let L be the event that both the tickets bear a number greater than 35 and an even number
Favourable points are 36, 38, 40, 42, 44, 46, 48, 50
There are 8 favourable points
∴ n(L) = 8C2 = 28
By the definition P(L) = n(L)/n(S) = 28/1225 = 4/175
Therefore the probability that both the tickets bear a number greater than 35 and an even number is 4/175
k) both the tickets bear an even number and multiple of 5
Let M be the event that both the tickets bear an even number and multiple of 5
Favourable points are 10, 20, 30, 40, 50
There are 5 favourable points
∴ n(L) = 5C2 = 10
By the definition P(M) = n(M)/n(S) = 10/1225 = 2/245
Therefore the probability that both the tickets bear an even number and multiple of 5 is 2/245
In the next article, we shall study some basic problems of probability based on the drawing of a single card from a pack of playing cards.