Sum of all the factors of 36 equals to ?

Question

Sum of all the factors of 36 equals to ?

 

My answer is 91 but in the book answer is 90.

I think answer is wrong.

Answer 1

First list ALL of the factors of the number 36.

 

1, 2, 3, 4, 6, 9, 12, 18, 36

 

The sum of all of the listed factors is 91. 

 

You are correct.  Your book made a mistake.

Answer 2

factors of 36= 1,2,3,4,6,9,12,18,36

 

91 is correct answer