7 4K ≡ (mod 100 )
(a ) 4
(b ) 2
(c) 3
( d ) 1

I assume you're asked to find for positive integer k. To start, notice that

Then for every k, we have

1^3 + 2^3 + 3^3 +4^3 = (1+2+3+4)^2

step-by-step explanation:

i am only able to answer the first part. i am not sure about the second part. sorry