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on question 65 of the 13th edition of the official guide how exactly does 2/4 * 10 to power 10 result in 5.9 *10 ^9
Let's first use a few brackets to avoid ambiguity.[email protected] wrote:on question 65 of the 13th edition of the official guide how exactly does 2/4 * 10 to power 10 result in 5.9 *10 ^9
The OG13 isn't saying that (2/4)(10^10) equals 5.9 x (10^9)
The solution for question #65 uses approximation to avoid lengthy calculations. This is okay, because the answer choices are sufficiently spread apart.
So, (2/4)(10^10) = (0.5)(10^10) = (0.5)(10^1)(10^9) = (5)(10^9)
When we check the answer choices, answer choice E, 5.9 x (10^9), is the only one close to (5)(10^9), so E must be the correct answer.
Aside: If you're interested, we have a free video on when it's safe to estimate on the GMAT: https://www.gmatprepnow.com/module/gener ... es?id=1111
Cheers,
Brent
