GMAT past paper - Percentage/Sets??

[akay]

Seems easy but foxed

On a certain road 10 percent of the motorists exceed the posted speed limit and receive speeding tickets but 20 percent 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 ½ %
(B) 12 ½ %
(C) 15 %
(D) 22 %
(E) 30 %

[beny]

B.

[smushkas]

This is a bit unclear, but if you think you can get the answer I think.
1) only 10% exceed the limit (they are registered for sure)
2) 20% do not receive the ticket (these ones are not registered)

Thus, 10% / 80% = 12.5% portion of total drivers who exceed the speed limit.
Any other approaches are welcome!

[jayhawk2001]

Please check https://www.beatthegmat.com/viewtopic.php?t=3633

[akay]

tks Jayhawk.