Q20 of 47 Page 1

From all the two-digit numbers, a number is chosen at random. Find the probability that the chosen number is a multiple of 7.

The total number of two digits = (99 – 10) + 1 = 90 numbers

We have to find the probability that the chosen number is a multiple of 7.


The number less than 99 which is divisible by 7 = 98


The number more than 10 which is divisible by 7 = 14


So, the numbers which are divisible between 10 and 99 by 7 = (98 – 14) /7 + 1


= 84/7 + 1


= 13


We know that the theoretical (classical) probability of an event E, written as P (E), is defined as P (E) = Number of outcomes favorable to E / Number of all possible outcomes of the experiment


P (a random 2-digit number divisible by 7) = 13/90


Answer: The probability that the chosen number is a multiple of 7 is 13/90.


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