Verified Answer :

In
the given number : 4 083 817. Find the 3 digit which is placed in the unit
period.

=> The unit period is the digit that is placed in the ones place of the
number or the first digit on the right.

=> 7 is the unit period

=> 3 is the another unit period

=> 4 is the another unit period.

Thus, 4, 3 and 7 are the 3 digits placed in the unit period of the given
number.