Please provide solution for this GMATPREP question:
On a certain road 10% 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 percentage of the motorists on that road exceed the posted speed limit?
A) 10 & 1/2%, B)12 & 1/2%, C)15%, D)22%, E)30%
The question appeared ambiguous to me hence couldn't solve it correctly.
GMAT PREP question
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- earth@work
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IMO 30%, whats the answer... i used venn diag to solve it.
overspeed ONLY=20
ticket + overspeed = 10
total overspeed = 30%
overspeed ONLY=20
ticket + overspeed = 10
total overspeed = 30%
- earth@work
- Master | Next Rank: 500 Posts
- Posts: 248
- Joined: Mon Aug 11, 2008 9:51 am
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IMO 30%, whats the answer... i used venn diag to solve it.
overspeed ONLY=20
ticket + overspeed = 10
total overspeed = 30%
do let me know if this is incorrect-then will try solving again
overspeed ONLY=20
ticket + overspeed = 10
total overspeed = 30%
do let me know if this is incorrect-then will try solving again
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A different variation of that would be:
Let the total motorists be 100 on the road
10% exceed speed limit and receive tickets So lets say 10
Let x be the total number of motorists on the road who exceed the speed limit(some get tickets and some dont and we know 10 out of this x gets tickets)
20% of x exceed the speed limit but dont get tickets
Therefore 10+ .20x (20% of x) = x
.8x = 10
x = 100/8 = 12.5 %
Let the total motorists be 100 on the road
10% exceed speed limit and receive tickets So lets say 10
Let x be the total number of motorists on the road who exceed the speed limit(some get tickets and some dont and we know 10 out of this x gets tickets)
20% of x exceed the speed limit but dont get tickets
Therefore 10+ .20x (20% of x) = x
.8x = 10
x = 100/8 = 12.5 %
- earth@work
- Master | Next Rank: 500 Posts
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