Cracking The SAT Premium

C,  and then    use Process of  Elimination.

18. 
    

    A Start with the easiest piece of information first, and use Process of Elimination. Since h is
    the number of hours spent hiking and d is the number of hours driving, the total number of
    hours Lennon spends in the park can be calculated as h + d. The question states that Lennon
    has up to 6 hours to spend in the park—“up to” means ≤. So, h + d ≤ 6. Eliminate (B), (C),
    and (D). The correct answer is (A).

    
    


19. 
    

    B The quality control expert discovered that 13 out of 1,000 randomly selected tennis balls

    
    

were    defective.      =   0.013,  which   is  equivalent  to  1.3%.   This    means   that    100 –   1.3 =

98.7%   of  tennis  balls   tested  were    not defective,  and this    data    most    supports    (B),    which   is

the correct answer.

20. C When solving inequalities, the natural impulse is to isolate the variable. In this case, though,

look    at  what    the question    is  asking. The question    doesn’t want    you to  find    just    the the value

of  z   but rather  the value   of  9z  –   18. To  get from    the value   of  –3z +   6   given   in  the inequality

to  this    new value,  the original    inequality  must    be  multiplied  by  –3. Just    multiply    the entire

inequality   by  this    value,  making  sure    to  flip    the     inequality  signs   when    multiplying     by  a

negative    number. The equation    becomes –3      >   –3(–3z  +   6)  >   –3      or      >   9z

–   18  >    .  The question    asks    for the greatest    possible    integer value,  so  focus   on  the high

end of  the given   values. The value   at  that    end,     ,  equals  8.57,   so  the greatest    integer less

than    that    is  8.  The answer  is  (C).

21. A Whenever there are variables in the question and numbers in the answer choices, think
    Plugging In the Answers. In (A), j = 6, and k = –6. Plug these two values into the first
    equation to get –24 – 8(6) = 12(–6). Solve for both sides of the equation to get –24 – 48 = –
    72, or –72 = –72. Therefore, the values work for the first equation. Plug the values into the
    second equation to get 3 + (–6) = – (6). Solve both sides of the equation to get 3 + (–10)

=   –7, or  –7  =   –7. Since   the values  given   in  (A) work    in  both    equations,  the correct answer

is  (A).

22. C You know the new proportion must be less than the current 0.34 for biofuels (because the

total   amount  spent   on  alternative energy  is  increasing, but the amount  spent   on  biofuels    is

remaining   the same),  so  you can eliminate   (D).    Next,   determine   the amount  that    will    be