Solution:
As the Options are not given
6 + (-8)
It means Ahmed is on the Sixth floor, above the ground floor and then goes 8 floor Downwards which is 2 level below the ground floor.
The Answer in form of numbers is = -2
Because when we add a positive integer and a negative integer , we just subtract smaller integer from larger integer , and keep that sign before the result which the larger number bears.
6 + (-8)=
8 is larger integer which bears negative sign.
One integer is positive and another one is negative,
8 -6= 2
So, 6 + (-8) = -2 →→ 2 level below the ground level
I have drawn number line for you.