Finding the digit at unit place in the given product

Property 6 The units digit of the square of a natural number is the units digit of the square of the digit at units place of the given natural number.

Find the digit in units place of the number 75^(2)

Find the digit in units place of the number 157^(2)

Find the digit in units place of the number 206^(3)

The digit in the unit place in the cube of 23 is

Find the digit in the units place of (676)^99 .

The sum of a two digit number and the number obtained by interchanging the digits is 99. If the digit at tens place exceeds the digit at units place by 3, find the number.