Unit digit of 1³+2³+3³+...+9³ is

What is the last digit of the sum S = 9²⁷ + 27⁹ ?

The unit digit in the product (281 × 15 × 16 × 18) is :

What is the digit at the 100th place of number (225)⁴⁰ ?

When 100²⁵−25 is written in decimal notation, sum of digits is

The value of a 2-digit number is 5 times the sum of the digits. What is the product of the digits ?