Question

An octal number (that is, a number written in base 8), is a number written with digits from the set {1,2,3,4,5,6,7,8}. How many octal numbers of 11 digits are there?

Answer 1

8589934592

Explanation:

Given:

Set of octal numbers = { 1, 2, 3, 4, 5, 6, 7, 8}

total number in the set = 8

Now,

The number is to be formed of 11 digits

i.e

we have 11 places to fill will the numbers given in the set

thus,

we have 8 choices for the single place in an 11 digit number

therefore,

total number of octal number that can be formed = qⁿ

here,

q is the number of choices

n is the number of places to be filled

thus,

total number of octal number that can be formed = 8¹¹

or

8589934592 octal numbers of 11 digits can be there