Question

What does “the digit of the units place of the sum” mean?

Answer 1

The unit place digit placed on the ones position of the particular number.

:)

Answer 2

The units digit of a number is the rightmost digit of the number.

Explanation:

the sum of the digits in the unit's place of all numbers formed with the help of 3,4,5,6 taken all at a times is 18+24+30+36=108.