Question

Solve the sum:-

What is its units digit ?

1^5 + 2^5 + 3^5 .......... 99^5

Answer 1

Power of 1^5 = 1. Hence Units digit  = 1.

Power of 2^5 = 32 - Hence units digit = 2.

Power of 3^5 = 243 - Hence units digit = 3.

|
|
|
|
|
|
|
|
|
|
|
.


Therefore:

 Sum = 99(99 + 1)/2

          = 4950


Hope this helps!

Answer 2

Hi,

Please see the attached file!


Thanks