Question

A number is selected at random from the first $1,000$ natural numbers. What is the probability that the number so selected would be a multiple of $7$ or $11$?

• A. $0.25$
• B. $0.32$
• C. $0.23$
• D. $0.33$

Answer 1

Answer: (C)

$0.23$

Number of multiples of 7 from 1 to 100 $=142$

Number of multiples of 11 from 1 to 100 $=99$

Number of multiples of 77 = 12

So, number of multiples of 7 or 11

$=142+99-12$

$=229$

Probability $=\frac{229}{1000}$ = 0.229