Hi sud21,
While this prompt 'looks' complex, it's actually a 'gettable' question IF you recognize the point that the chord intercepts...
We're told that the circle is CENTERED at the ORIGIN (so the circle is symmetric around the Origin) and that the chord in question intersects the circle at the X-axis.
When a point is on the X-axis, it's Y-co-ordinate is 0. Thus, since the equation of the chord is....
x+3√y=5
X + 0 = 5
X = 5
The X-intercept of the end-point on that chord is 5. Since the circle is symmetric around the Origin, the radius of the circle is 5. The formula for Circumference of a circle is...
Circumference = 2(pi)(radius) = 2(pi)(5) = 10pi
Final Answer: E
GMAT assassins aren't born, they're made,
Rich
