Remark
This will be a little late, but I'll answer it anyway. The more you see of the sine law, the clearer it will be.
Step One
Set up the sine Law.

Step Two
Substitute values
Sin(x) = ??
sin(75) = 0.9659

Step Three
Cross multiply and Solve
22* Sin(x) = 12 * 0.9659
22* Sin(x) = 11.591 divide by 22
sin(x) = 11.591 / 22
sin(x) = 0.5269
Step Four
You have to know how to use the inverse of an angle to get the answer. I do it as my calculator would do it. If it doesn't work with yours, let me know.
x = sin^-1(0.5269)
2nd F
Sin^-1
(
0.5269
)
=
You should get 31.79 degrees.
The number of handshakes is the number of ways 6 objects can be selected 2 at a time.
.. C(6,2) = 6·5/(2·1) = 15
The appropriate choice is
... C) 15
_____
Consider that each person can shake hands with 5 others. That's a total of 6*5 = 30 handshakes, but it counts both A shaking with B and B shaking with A. If each pair of persons only shakes hands once, the number of handshakes is 30/2 = 15.