Question

The digit inthe unit's place of the number represented by 7^55-3^29 is

Answer 1

Answer:

4

Step-by-step explanation:

If you see the power of 7 then you will notice a sequence:

7¹=7

7²=49

7³=343

7⁴=2401

7⁵=16807

7⁶=117649

And the unit digits keep on repeating as  

{ 7, 9, 3, 1 }

It repeats after every 4 powers , So divide 55 by 4

You will get 3 as the remainder .

The third number in the series is 3.

This implies the unit digit of 7^55 is 3 .

Similarly, do for 3^29

3¹=3

3²=9

3³=27

3⁴=81

3⁵=243

And the unit digits keep on repeating as

{ 3, 9, 7, 1 }

Now divide 29 by 3 and get the remainder as 2

Second number in the series is 9.

This implies unit digit of 3^29 is 9

Unit digit of 7^55−3^29 = 3−9 = 13-9 (borrow from the previous digit)

= 4

Hope this helps !

Thanks !

Answer 2

Answer:

search in google ,,you will get better answer