We will solve different type of problems on probability of rolling a die.
1. A die is thrown 200 times and the numbers shown on it are recorded as given below:
If the die is thrown at random, what is the probability of getting a
(i) 4
(ii) 4 or 5
(iii) Prime number
Solution:
(i) Total number of trials = 200.
Number of times 4 appears = 28.
Therefore, the probability of getting 4 = \(\frac{\textrm{Frequency of 4 Appearing}}{\textrm{Sum of all the Frequencies}}\)
= \(\frac{\textrm{Number of Times 4 Appears}}{\textrm{Total Number of Trials}}\)
= \(\frac{28}{200}\)
= \(\frac{7}{50}\).
(ii) Total number of trials = 200.
Number of times 4 or 5 appears = 28 + 26 = 54.
Therefore, the probability of getting 4 or 5 = \(\frac{\textrm{Number of Times 4 or 5 Appears}}{\textrm{Total Number of Trials}}\)
= \(\frac{54}{200}\)
= \(\frac{27}{100}\).
(iii) Total number of trials = 200.
Number of times a prime number appears = 48 + 36 + 26 = 110.
[Since 2, 3 and 5 are prime numbers and they appear 48, 36 and 26 times respectively).
Therefore, the probability of getting
a prime number = \(\frac{\textrm{Number of Times a Prime Number Appears}}{\textrm{Total Number of Trials}}\)
= \(\frac{110}{200}\)
= \(\frac{11}{20}\).
● Probability
8th Grade Math Practice
From Probability of Rolling a Die to HOME PAGE
Didn't find what you were looking for? Or want to know more information about Math Only Math. Use this Google Search to find what you need.
Apr 20, 24 05:39 PM
Apr 20, 24 05:29 PM
Apr 19, 24 04:01 PM
Apr 19, 24 01:50 PM
Apr 19, 24 01:22 PM