524,818 views
24 votes
24 votes
72b384 is a number in which one of its digits is 'b'. if the number is a multiple of 9, what is the numerical value of 'b'?

User Fredy Treboux
by
2.9k points

1 Answer

19 votes
19 votes

Answer:

3

Explanation:

Hello!

A simple way to find if the number is a multiple of 9 is if the sum of the digits in the number is a multiple of 9, then the number itself is a multiple of 9.

So that means: 7 + 2 + b + 3 + 8 + 4 is a multiple of 9

If we add it up we should get: 24 + b

The multiples of 9 include 9,18,27,36,45,54....., and the closest multiple of 9 to 24 is 27. Therefore, the missing digit should be 3, as 27 - 24 is 3.

The next closest numbers would be 18 and 36, but you would need to add a negative number to get 18, and a two-digit number to get 36.

User Weiwei
by
2.9k points