## Link of the Day

Elections
in the United States are generally taken as a matter of course, but this is not
true in many other nations. Right now
Kenyans are waiting to see the results of an election that, although violent,
has so far been much more peaceful than the elections in 2007 that left over a
thousand dead. Read this article and think
about all the complexities involved in this story – especially about what it
means to have a credible leader. Think
about the themes of progress, respect for humanity, the role of citizens and
leaders in society, courage, and the motivations behind actions. This story has many connections to themes
that show up frequently in SAT essay questions.
Think about the people who are waiting for the results, and follow up on
this story as it progresses.

## Arithmetic: Multiples

*Read the following SAT test question and then select the correct answer.*

Approach
each problem the same way so that you feel confident about your ability to
solve it. Start by reading the question
carefully and identifying your bottom line.
Then assess your options and choose the most efficient method to attack
the problem. When you have an answer,
loop back to verify that the answer addresses the bottom line.

*Add 8x to 2x and then subtract 5 from the sum. If x is a positive integer, the result must be an integer multiple of*

**Bottom Line**: multiple of = ?

**Assess your Options**: You have to write an equation for this problem, but after doing so you can use logic or the strategy of plugging in numbers to find possible answers to the equation. Both methods are quick and will result in the correct answer.

**Attack the Problem**: Your first step is to translate all the words you are given into an equation. If you add 8

*x*to 2

*x*, you get 8

*x*+ 2

*x*. Then subtract 5. You should have:

8

*x*+ 2*x*– 5
Always simplify as much as
possible before moving to the next step.
Here, you can combine like terms.

10

*x*– 5
Now go back to the other
information that you are given. The
variable

*x*must be a positive integer. Plug in the smallest possible value for*x*, and you will get the smallest possible result of this equation. Plug in*x*= 1.
10(1) – 5 = 5

Now, multiples will always
get larger, so there are other possible answers to this equation. However, this is the smallest answer and you
are looking for what the result “must” be an integer multiple of. Multiples are simply the product of a number
and an integer. 5 is a prime number, so
the only thing that the answer must be a multiple of is 5.

(If you want to make sure
you are on the right track, plug in x = 2.
The answer is 15. 15 is still a
multiple of 5. Any positive number that
you plug in will still be a multiple of 5 because when you subtract 5 from a
multiple of 10, you will always get a number ending in a 5.)

**Loop Back**: You found that the answer must be a multiple of 5. Look down at your answer choices.

(A) 2

(B) 5

(C) 8

(D) 10

(E) 15

The correct answer is (B).

On sat.collegeboard.org, 68% of the
responses were correct.

For more help with SAT math, visit www.myknowsys.com!