What is the ones digit in the number 3^20997

7

Step-by-step explanation:

3^0 = 1

3^1 = 3

3^2 = 9

3^3 = 27

3^4 = 81

3^5 = 243

3^6 = 729

3^7 = 2187

3^8 = 6581

You can see that the pattern is beginning to repeat itself.

So all you need do is take 2099 and divide by 3. You must pay attention to the remainder.

2099 / 4 = 524.75

The answer means that you go through the cycle 524 times getting 1,3,9,7,1 as the units digit.

In this case the remainder is 0.75 which is the same as 3/4. The remainder then is 3

If there is no remainder, the ending is a one.

if there is a remainder of 1 the answer is 3

If there is a 2 remainder, the number ends in 9

If there is a 3 remainder, the number ends in 7

And that's your answer.

1.0

step-by-step explanation: