by yuanshi » Sun Apr 18, 2010 11:52 pm
Sixty students, including # and Jane, are to be split into three classes of equal size. What is the probability taht # and Jane will be in the same calss, provided that the split is done randomly?
a 33.0% b 32.2% c 27.7% d 21.5% e 10.9%
Let x, y, and z be positive integers such that one of the interges is twice one of the other intergers. If the aritmetic mean of x,y, and z is 11 and the geometric mean of x,y, and z is 6, then the harmonic mean of x,y, and z is _____.
a 4.5 b 3.3 c 7.8 d 4.4 e 3.8
A Ferris wheel has a radius of 7 meters and turns at 6 revolutions per minute. The bottom of the Ferris wheel is 1 meter above the ground. The height h of a passenger above the ground varies sinusoidally with time t. which of the following equations best describes the relationship between h and t?
a h=6+7cos(π/6*t) b h=8+7sin(π/5*t) c h=7-6cos(π/5*t) d h=7-8sin(π/3*t) e h=8-7cos(π/5*t)
I'm trying to learn how to do these before regionals, so if you could help before then, that'd be great! :D I might add more later if I have more troubles (which probably will happen.)