Find the remainder 21 ^231 divided by 25.Please post ur Approach. Thnks.

1) 4
2) 16
3) 1
4) none of these

• 21^231
  As it is one at end of 21,whatever the power be, resulting number shall always have 1 at units place
  Now finding the tens place of resulting number
  That will be tens digit of the number (ie 2) multiplied to units digit of the power (ie 1)
  There is a detailed article on finding tens digit of a power at total gadha website, be sure to check out
  So the resulting number is ______21
  Now 25 multiples end with either 00,52,50,75
  As dividend ends with 21,we divide by a number ending with 00
  Therefore remainder is 21
  So none of these is the answer
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