Khan/khan-exercises — Issue #9158: Adding and subtracting decimals word problems - Adding and subtracting decimal word problems
Author: KhanBugz
Created: 2011-12-21 03:34:26+00:00
State: open
Labels: firefox, wrong-or-unclear, xp

Reporter: rghein@gmail.com

Here is the question:

On Monday, Stephanie and Vanessa decided to see how fast they could sprint 200 meters. They asked their friend William to time them with a stopwatch.

After 1.58 minutes, William agreed to time the runners. Stephanie sprinted first and ran 200 meters in 62.67 seconds. When it was Vanessa's turn, she sped off and completed the run in 52.6 seconds.

How much faster was Vanessa than Stephanie?

My problem:

The correct answer is given as 10.07. I think this question is wrong/unclear. Yes, Vanessa ran 200m 10.07 seconds faster than Stephanie.

But, she was not 10.07 times faster than Stephanie.

Acceptable answer formats are given as integer, fraction, decimal. There is no mention of any units desired in the answer.

If we can arbitrarily choose units, we could also say that Vanessa ran 3.80 m/s and Stephanie ran 3.19 m/s, so Vanessa was .61 m/s faster than Stephanie.

This is too ambiguous.

Thanks for your attention.

[adding_and_subtracting_decimals_word_problems.html?seed=150&problem=1](http://sandcastle.khanacademy.org/media/castles/Khan:master/exercises/adding_and_subtracting_decimals_word_problems.html?seed=150&problem=1&debug)

[Answer timeline](http://sandcastle.khanacademy.org/media/castles/Khan:master/exercises/adding_and_subtracting_decimals_word_problems.html?seed=150&problem=1&debug&activity=%5B%5B%22correct-activity%22%2C%22%5C%2210.07%5C%22%22%2C228%5D%5D)

["10.07"]

Mozilla/5.0 (Windows NT 5.1; rv:8.0) Gecko/20100101 Firefox/8.0

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