Question 26
With some 3-digit numbers, the third digit is the sum of the first two digits. For example, with the number 213 we can add 1 and 2 to get 3, so the third digit is the sum of the first two digits.
How many 3-digit numbers are there where the third digit is the sum of the first two digits?
How many 3-digit numbers are there where the third digit is the sum of the first two digits?