Question

If $64=x^y$, where $x>y,x\ne 4$ and
$y\ne 1$ then x + y =

• A. $7$
• B. $4$
• C. $8$
• D. $10$

Answer 1

The correct option is D $10$

$64$ can be written as ${64}^1,8^2,4^3,2^6$
As $x>y$
Possible options of writing $64$ are ${64}^1,8^2,4^3$
Since, $x\ne 4$,
From the chosen options, Possible options of writing $64$ are ${64}^1,8^2$
Since, $y\ne 1$,
From the chosen options, Possible options of writing $64$ is only $8^2$
So, $x=8,y=2$
$=>x+y=10$