4^3 + 4^3 + 4^3 + 4^3 =

Hi shakticnb,

Certain Quant questions on the GMAT are just about 'organizing' the information in a specific way. If you find yourself getting confused by a prompt, think about how you might change the way that the information is presented to you.

Here, for example, we're asked for....

4^3 + 4^3 + 4^3 + 4^3 =

Now, the GMAT doesn't really expect us to calculate this sum (but we could if we had to), but we are expected to find a way to organize this information... If, instead of all of those exponents, we had...

X + X + X + X =

What would the sum be?

Clearly, it would be 4(X) = 4X.....since we're just combining 'like' terms. Take that same idea with this prompt and you have...

4^3 + 4^3 + 4^3 + 4^3 =

4(4^3)

This can be re-written as...

(4^1)(4^3)

...and now we can use exponent rules; since we're MULTIPLYING 'bases' that are the same, we ADD the exponents...

(4^1)(4^3) = 4^4

Final Answer:

GMAT assassins aren't born, they're made,
Rich

4^3 + 4^3 + 4^3 + 4^3

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

= 4^3 (4^1 )

= 4^4

Hence answer will be (A)

\(4^3 + 4^3 + 4^3 + 4^3 = 4^3 (1 + 1 + 1 + 1 ) = 4^3 * 4 = 4^4\)

Answer A