If the city centers of New York and London are 3,471 miles apart, whic

3471 miles = 5280*3471 feet
but we need answer in inches
thus:
5280*3471*12 inches ~= 5300*3500*12 = 1.855*10^7 *12 = 2.2 *10^8

Ans: C

1 feet = 12 inches
1 mile = 5280 feet = 5280*12 inches = 63360 inches = 6.3*10^4 inches (approx)
—> 3471 miles = (3.5*10^3)*(6.3*10^4) approx
= 3.5*6.3*10^7
= 21*10^7 approx
= 2.1*10^8

IMO Option C

 

I'd like to believe that I have the simplest (which would also translate to the "fastest") solution to this:

Whenever there's which of the following is closest / approximately , I'd suggest you go aggressive with rounding and estimating to save the most critical thing in the GMAT, i.e. "time", since it's very obvious that by giving this question - GMAT isn't really intending to check whether you know "how to multiply", rather it wants to see how fast you can do it

So here's what I did, 3471 ~3500 miles and 5280 feet in a mile ~ 5000 feet in a mile, now I straight went for 3500 * 5000 or 35*5*10^5, now I have 175*10^5

Now getting down to the "inches" part, 175*10^5*12, I have 2100*10^5, which quickly gives me 2.1*10^8 and I look up the options and hit (D) - 30 seconds, and I move on
 

The conversion for feet to inches is the following:
\(1 foot = 12 inches\)

\(3471 miles * \frac{5280 feet}{1 mile}\)

\(= 3471 * 5280 feet * \frac{12 inches}{1 feet}\)

\(= 3471*5280*12 inches\)

You are told to approximate.
3471 ~ 3500
5280 ~ 5000
12 ~ 10

\(3500 = 35 * 100\)
\(5000= 5 * 1000\)
\(10 = 10\)

\(3500 * 5000 * 10 \)
\(= 35*100*5*1000*10\)
\(= 35*5*10^6\)
\(= 175 * 10^6\)
\(= 1.75*10^8\)

Glancing at the answer choices, the closest choice to what we got is C.

Thus, C is the answer.

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