The number 18
18
(a+b)*2=10a+b b=8a, a=1, b=8 18 is the only answer
I'm thinking of a number.
What is the number?
When a two digit number is multiplied by sum of its digits, the product is 715 but when the reverse of a two digit number is multiplied by sum of its digits the product obtained is 99 less. What is the sum of the digits of a number?
The sum of the digits of a three digit number is 17, and the sum of the squares of its digits is 109. If we subtract 495 from the number, we shall get a number consisting of the same digits written in the reverse order. Find the number.
