Read Up Your Score Online

Authors: Larry Berger & Michael Colton,Michael Colton,Manek Mistry,Paul Rossi,Workman Publishing

Up Your Score (34 page)

BOOK: Up Your Score
2.44Mb size Format: txt, pdf, ePub
ads

Examples:

x
exceeds
y
by 7                    means
x

y
= 7 or
y
+ 7 =
x

x
is greater than
y
by 7          means
x

y
= 7 or
y
+ 7 =
x

Rule 3:
Percent
(%) usually goes with
of
.

Remember that
percent
means
per hundred
, so a percent problem is really just a problem with fractions. They tell you the numerator and give you the “%” sign, which you translate into meaning “over one hundred.” For example, 25% is really
, which is a fraction.

25% of
y
becomes
of
y
(remember
of
means multiply), so it’s
×
y
or, if you’re using a calculator, .25 ×
y
.

Do the same thing for percentages greater than 100%. For instance, 250% means
, or 2.5.

Rule 4: But wait, there’s
more
. Percent can be made trickier with the word
more
.

If Sue has 25%
more
apples than Bill, then she has
as many
apples as Bill
plus
25% more. So the word
more
can be broken down into “
as many
——
plus
——.”

But we can do better than apples:

Bill has exactly 8 pairs of underwear, all of which
are sexy. Sue has 50% more pairs of underwear
than Bill. 75% of Sue’s total collection of underwear
is sexy.

Who has more sexy underwear? (Don’t get distracted.)

Here’s the answer:

By Rule 4, Sue has
as many
pairs as Bill
plus
50%.

So, Sue has 8 pairs +
of 8.

Sue has 8 + 4 = 12 pairs of underwear.

75% of her 12 total pairs of underwear is sexy.

Using Rule 3, this becomes
of 12.

And finally, using Rule 1, this becomes
× 12 = 9.

Sue has 9 pairs of sexy underwear and Bill has 8, so Sue has more. But they both have about as much fun.

Rule 5: There’s even more.
Percent increase or decrease
means subtract or add.

Jim has $50.00, which he invests wisely; it increases by 10%. How much money does he now have?

Percent means per hundred, so a 10 percent increase means that you add 10% of the original number. 10% of $50 is $5, so $50 + $5 = $55.00. The same holds true for percent decrease.

Rule 6:
Ratio
—okay, so what’s a ratio? A ratio is just a comparison.

If you say
y
>
x
then you’re comparing
y
and
x
and finding out that
y
is larger than
x
. (And, you might ask, who really cares?)
But
y
>
x
is not a ratio. Ratios involve “division comparisons”:

“the ratio of
y
to
x
is 5” means
= 5

Here,
y
is being compared to
x
. Again
y
is bigger—but now we know that
y
is five times bigger. (Wow. Excitement.) This expression could also be written:


y
is to
x
as 5 is to 1” or
y
:
x
as 5:1

Okay, well, how
is
5 to 1? 5
is
five times as big as 1 (obviously). So
y
is five times
x
, get it?

It’s probably easiest to think of this as a fraction:

BOOK: Up Your Score
2.44Mb size Format: txt, pdf, ePub
ads

Other books

For His Trust by Kelly Favor
Ghost Hunters by Sam Witt
Mystic City by Theo Lawrence
Save Me From Myself by Stacey Mosteller
Exiles by Cary Groner


readsbookonline.com Copyright 2016 - 2024