Percentage on the SAT

How do we calculate SAT problems involving percent?

Question Number 1
SAT PROBLEM
4^th problem in a 25 problem section

A certain state requires that an applicant for a driver's license answer at least 80 percent of the questions on a written test correctly. If the test has 30 questions on it, at least how many of these questions must be answered correctly?

( Saturday/11.1996 #4) p. 370

Question Number 2
SAT PROBLEM
#7 in a 25 problem section

What percent of 50 is 6?

3 %
8.33%
12%
30%
88.33%

( Saturday/1.200) p.524

Question Number 3
SAT PROBLEM
#7 in a 25 problem section

If r is 35 percent of p and s is 45 percent of p, what is r + s in terms of p?

0.4p
0.5p
0.6p
0.7p
0.8p

( Saturday/1.2000 #7) p.524 *

Question Number 4
SAT PROBLEM
9^th problem in a 25 problem section

What percent of 50 is 6?

(Sunday/5.1997 #4) p. 484

Question Number 5
SAT PROBLEM
#11 in a 25 problem section

75 percent of 88 is the same as 60 percent of what number?

( Saturday/1.1997 #11) p. 405 *

Question Number 6
SAT PROBLEM
#17 in a 25 problem section

A store has 660 bocks in stock. If 30 percent of these books are on sale, how many books are not on sale?

(Student Generated Response)

( Saturday/5.2002 #17) p. 665 *

Question Number 7

SAT PROBLEM

A total of 60 advertisements were sold for a school yearbook. If 20 percent of the first 20 sold were in color, 40 percent of the next 30 sold were in color, and 80 percent of the last 10 sold were in color, what percent of the 60 advertisements were in color?

Question Number 8

SAT PROBLEM
(#13 of 25)

If x > 0, what is 30 percent of 15x?

0.5x
2x
4.5x
5x
45x

( Saturday/11.1996 #13) p.372 *

Question Number 9

HARD SAT PROBLEM:

A dress is selling for $100 after a 20 percent discount. What was the original selling price?

$ 200
$125
$120
$80
$75

( taken from Princeton Review's Cracking the New SAT ) #17

Question Number 10

MEDIUM-HARD SAT PROBLEM
The percent increase from 8 to 14 is equal to the percent increase from 20 to what?

(#7 out of 10 Satuday/1.2002 SAT) p.637

Question Number 11

SAT PROBLEM
( 7^th out 10 problems)

Pat has s grams of strawberries and uses 40 percent of the strawberries to make pies, each of which requires p grams. The rest of the strawberries are used to make pints of jam, each of which requires j grams. Which of the following gives the number of pints of jam Pat can make?

(2s)/5p
(2s)/5j
(3s)/5j
(3p)/5s
(3sj)/5

(Sunday/5.1997 SAT) #7 p. 508 *

Question Number 12
HARD SAT PROBLEM
(22nd out of 25 problems)

A person slices a pie into k equal pieces and eats on piece. In terms of k, what percent of the pie is left?

Question Number 13

HARD SAT PROBLEM
( 21^st out of 25s)
S is the sum of the first 100 consecutive positive even integers, and T is the sum of the first 100 consecutive positive integers. S is what percent greater than T ?

100%
50%
10%
2%
1%

(Sunday/5.2002 SAT) #21 p. 575

Question Number 14
HARD SAT PROBLEM
( 25 ^th problem out of 25 problems )
A store charges $28 for a certain type of sweater. This price is 40 percent more than the amount it costs the store to buy one of these sweaters. At an end-of-season sale, store employees can purchase any remaining sweaters at 30 percent off the store's cost. How much would it cost an employee to purchase a sweater of this type at this sale?

$ 8.40
$14.00
$19.60
$ 20.00
$ 25.20

(Saturday/5.1997 SAT #10) p. 472