Question

Rich chooses a 4-digit positive integer. He erases one of the digits of this integer. The

remaining digits, in their original order, form a 3-digit positive integer. When Rich
adds this 3-digit integer to the original 4-digit integer, the result is 6031. What is the
sum of the digits of the original 4-digit integer?

Answer 1

*step by step*

Explanation:

If he erases one of the digits in a 4-digit number, then only 3 remain, not four.

If he erased the first digit, then it must have been 1-9, so the total is in the range 11 - 19

otherwise the digit could have been 0-9 in which case the total is in the range 10-19