Percent Problem

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Percent Problem

by smallsorrow » Mon Sep 22, 2008 7:03 am
On a certain raod 10% of the motorists exceed the posted speed limit and receive speeding tickets, but 20% of the motorists who exceed the posted speed limit do not receive speeding tickets. What percent of the motorists on the road exceed the posted speed limit?

A) 10,5%
B) 12,5%
C) 15%
D) 22%
E) 30%

I have no idea how to get to the OA!

PS: its not 30!! :-)
Source: — Problem Solving |

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by stop@800 » Mon Sep 22, 2008 7:28 am
Ans is 12.5%
The same question is solved in last weeks posts.

Let me know if you want me to search for the same.

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by Travis_1234567890 » Mon Sep 22, 2008 7:30 am
You can rephrase the question to...

10% is 80% of what number?

Ans = B 12.5%

Let all speeders = X

You know that 20% of X gets no ticket
Since the other 80% X gets ticketed and we know that group represents 10% of people on the road, you can find the answer by taking 10/.8

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by smallsorrow » Mon Sep 22, 2008 7:42 am
Thanks Travis. This helps...

I did not get the question properly.