MathRevolution wrote:

How many hours it took the chip to compute 1 million mega-operations (mega-operations=1 million operations)

A. 3*10-5 B. 3*10-6 C. 3*10-7 D. 3*10-8 E. 3*10-9

→ From 1.026*10^16:1 sec=1 million mega-operation:n=10^6*10^6:n, it becomes n=10^12/1.026*10^15 sec. That is, 10^12/1.026*10^15 sec=10^12/(1.026*10^15*3,600)hr=3*10^-7 hr. Therefore, the answer is C.

I was about to support and reiterate Chetan4u's solution, but then I figured out where the typo is in the question!

The question is supposed to read:

A new computer chip can compute

\(1.026*10^{15}\) operations per second. How many hours will it take the chip to compute 1 million mega-operations (mega-operations=1 million operations)?

A. \(3*10^{-5}\)

B. \(3*10^{-6}\)

C. \(3*10^{-7}\)

D. \(3*10^{-8}\)

E. \(3*10^{-9}\)

Now we can answer the question the way it was intended.

We are told that a computer chip can perform \(1.026*10^{15}\) operations per second, and we are asked how many hours it will take for the ship to perform one million million operations (\(10^{12}\) operations). Since each of the answer choices are separated by a power of 10, then we can safely approximate \(1.026*10^{15} = 1*10^{15}\).

We can find the number of seconds it will take to perform \(10^{12}\) operations by dividing the number of operations by the number of operations per second:

\(\frac{12^{12}}{10^{15}} = 10^{-3}\) seconds.

Now to convert seconds to hours, we need to divide \(10^{-3}\) seconds by 3600 seconds per hour. Again, since the answer choices are spread out by powers of 10, we can approximate:

\(\frac{10^{-3}}{3.6*10^3} = \frac{10^{-6}}{3.6} ≈ 3*10^{-7}\)

So the answer should be C

Clear notation, like punctuation, makes all the difference...

_________________

Dave de Koos

GMAT aficionado