GRE Quant

Question 1

(a+b)^3=

Answer 1

a^3 + 3a^2b + 3b^2a + b^3

Question 2

(a-b)^3=

Answer 2

a^3 - 3a^2b + 3ab^2 - b^3

Question 3

x^a+x^b =

Answer 3

x^(a+b)

Question 4

(x^a)^b=

Answer 4

x^(ab)

Question 5

x^a•y^a=

Answer 5

(xy)^a

Question 6

|r + s| ? |r| + |s|

Answer 6

≤

Question 7

|r||s| ? |rs|

Answer 7

=

Question 8

Simple interest formula

Answer 8

V=P(1+(rt/100))

Question 9

Annually compounded interest formula

Answer 9

V=P(1+(r/100))^t

Question 10

Interest compounded n times annually

Answer 10

V=P(1+(r/100))^nt

Question 11

Area of a trapezoid

Answer 11

½(b1+b2)(h)

Question 12

Number of permutations of n objects

Answer 12

n!

Question 13

Number of permutations of size k, a subset of a set of size n

Answer 13

n!/(n-k)!

Question 14

Number of unordered permutations of size k, a subset of a set of size n

Answer 14

n!/(n-k)!k!

Question 15

Length of an arc of angle size a

Answer 15

(a/360)2πr

Question 16

Area of a sector of angle size a

Answer 16

(a/360)πr^2

Question 17

P(E or F) when not mutually exclusive

Answer 17

P(E)+P(F)-P(E & F)

Question 18

P(E or F) if mutually exclusive

Answer 18

P(E)+P(F)

Question 19

P(E&F) if independent

Answer 19

P(E)P(F)

Question 20

If you simplify a linear equation and get x=x, then

Answer 20

it’s an identity true for all x

Question 21

When do you reverse the inequality sign?

Answer 21

When multiplying or dividing by a negative number

Question 22

The interior angles of an n-gon sum to how many degrees?

Answer 22

(n-2)(180)

Question 23

The interior angles of a regular n-gon are all how many degrees?

Answer 23

(180(n-2))/n

Question 24

Standardization of a data set is the same as

Answer 24

finding the z-scores

Question 25

Is sample standard deviation the same as standard deviation?

Answer 25

no

Question 26

What are the valid triangle congruency sets?

Answer 26

SSS, SAS, ASA, AAS

Question 27

Pi can be approximated as

Answer 27

22/7 or 3.14

Question 28

A what is the relationship between the weighted mean and the arithmetic mean?

Answer 28

It's the same thing but instead of 7+7+7 it's 3•7

Question 29

What are the side ratios for a 45° right triangle?

Answer 29

1/1/root2

Question 30

What are the side ratios for a 30°/60° right triangle?

Answer 30

1/2/root3

Question 31

The coordinates of point B that is symmetric with point A=(a,b) across the y-axis are:

Answer 31

(-a,b)

Question 32

The coordinates of point B that is symmetric with point A=(a,b) across the x-axis are:

Answer 32

(a,-b)

Question 33

The coordinates of point B that is symmetric with point A=(a,b) across the origin are:

Answer 33

(-a,-b)

Question 34

The coordinates of point B that is symmetric with point A=(a,b) across the line y=x are:

Answer 34

(b,a)