Hi, there. I'm happy to give my 2¢ on this.
We want the
most left nonzero digit of N. Notice, the question is not even asking about the left most digit to the right of the decimal point. It's asking about the left most digit in the entire number.
When we add 8.xxx * 10^(-1) + 2.xxx * 10^(-1), we get a result greater than one. There's no way that the sum will be even greater than 2 --- it certainly will come nowhere near to 10.
I agree with
abby17 that the sum will be of the form 1.abcdef. I agree with
abby17 that the
right most digit, f, will depend on the value of x. BUT, the
left most digit would be the units digit of 1.
Therefore, the answer is (A) the units digit.
Does that make sense? Please let me know if you have any questions on what I've said.
Mike
