The unit's place digit in the expansion of (191)¹⁰⁰⁹ is

Calculations:

For finding the unit place of a number raised to an exponent, we only consider the unit place of the base number.

The unit place of any power of a number repeats after 4 exponents.

Here the base number is 191, its unit place is 1, and any power of 1 will always remain 1.

So, the unit's place digit in the expansion of (191)¹⁰⁰⁹ would be 1.