'09 TMSCA #4

[nsguy1350]

6. Joe's boat took 4 hours to go 64 miles downstream. Then it needed 16 hours to return where it started. Find the speed of the current.
D. 6 mph
27. Two chords, AC and BD, intersect in the interior of a circle at point P. If m<APD = 80 and m(arc)AB = 60,m find m(arc)CD.
D. 140
28. Find the area of the quadrilateral formed by conecting the points (-1,1),(-5,5),(6,4), and (8,-1) in order.
C.40.5
35. Find the x-intercept of the line tangent to [unparseable or potentially dangerous latex formula] when x = 1.
B. .25
42. (How did I miss this?!? I solved for x and y, but I'm not sure where I messed up. I tried multiple times.)
If [unparseable or potentially dangerous latex formula] and [unparseable or potentially dangerous latex formula] find 3y-x.
E.8
49. A circle is inscribed in a scalene triangle. The lengths of the sides are 16,18, and 24. Find the radius of the circle (nearest tenth).
D. 5.0

Did 50, missed 3, skipped 7 for a total of 294.

[Salvadoramerican]

49 heron's formula divided by the semiperimeter
I explain the quadrilateral
calculus that shouldn't give you trouble

the stream speed distance equals rate times time so for both trips
1st 64=r*4 r=16
2nd 64=r*16 r=4
now to include stream speed
(16-x)=(4+x) where the x goes in reality does matter but here it doesn't unless its physics so 2x=12 x=6