Question

what will be tge remainder if 7power2015 is divided by 25

Answer 1

Answer:

Step-by-step explanation:

Here,powers of 7 follows a cyclic series.We see that last digit of powers of 7 follows a pattern...7,9,3,1,7........

Now,we see for 7^(3k),remainder will be always 18 when divided by 25 for k=0,1,2,......

7^(2015) comes in the above series.

For k=0,1we see remainder as 18 when divided by 25.Similarly, for k=403,that is,7^(2015),we get 18 as remainder.Hope you understood

Answer 2

$\mathbb{ANSWER}$

$hope \: it \: helps \: you \:$

When divided by 25 ,x

71 leaves remainder 7

72=49 leaves 24

73=343 leaves 18

74=2401 leaves 1

75=16807 leaves 7

The remainders repeat (after every fourth power of 7 ). Now, 2015 can be written as 4∗503+3 .

7 ^ 2015=7 ^( 4∗503+3) will leave a remainder 18.

Thus, the remainder will be 18.