Question of the week 04-Mar-2020

Q) If 4^a + 4^b + 4^c + 4^d + 4^e = 20561, the value of "a+b+c+d+e" is

a)  16      b) 17         c) 18       d) None of these

Previous question here. Next week question here. It is solvable in less than a minute provided you know the trick that i will be discussing in the book. Your answer only with a logical explanation is welcomed in the comments section.