circle geometry
posted by Anonymous on .
Circles Γ1 and Γ2 intersect at 2 distinct points A and B. A line l through A intersects Γ1 and Γ2 at C and D, respectively. Let M be the midpoint of CD. The line MB intersects Γ1 and Γ2 again at E and F, respectively. If MA=129,MB=156 and MC=182, what is the value of EF?

I worked this earlier:
29*182 = ME*156, so ME = 33.8333
MD = MC = 129+182 = 311
MF*156 = 129*311, so MF = 257.173
EF = MF+ME = 33.833+257.173 = 291
Is my answer incorrect? 
Incorrect.

The correct answer is 301.
Steve, in the first line is 129, not 29... and you shouldn't work with decimals because in the end the ugly dominator simplifies with the numerator.