SAT Subject Test Mathematics Level 2

Another

way:

    +

Especially  in  a   complex problem such    as  this    one,    keep    track   of  where   you are in  the solution

process—you’re  not done    yet!    The fraction     represents the probability of  no  heads   or  one

heads;  you want    the probability of  getting two,    three,  four,   or  five    heads.  Recall  that    1   –

Prob 0   heads  or  1   heads   =   Prob2,  3,  4,  or  5   heads , so

Notice  that    this    is  quite   a   high    probability—more    than     ,  or  75%.    What    does    that    tell    you?

That    your    answer  was so  high    a   probability means   that    you were    smart   to  solve   using   the

indirect,   “1  minus”  approach    rather  than    the direct  approach,   which   would   have    entailed

writing out all the different   ways    a   fair    coin    tossed  five    times   could   have    landed  heads   up

two times,  and then    three   times,  and then    four    times,  and then    five    times.

10 . D
Re-express the equation in exponential form. The base is x, the exponent is 3, and the result
is 6:

11 . A

First   factor  the numerator   and denominator and cancel  common  factors: