All PSAT Math Resources
Example Questions
Example Question #1041 : Sat Mathematics
The square root of 5184 is:
72
73
74
71
70
72
The easiest way to narrow down a square root from a list is to look at the last number on the squared number – in this case 4 – and compare it to the last number of the answer.
70 * 70 will equal XXX0
71 * 71 will equal XXX1
72 * 72 will equal XXX4
73 * 73 will equal XXX9
74 * 74 will equal XXX(1)6
Therefore 72 is the answer. Check by multiplying it out.
Example Question #1042 : Sat Mathematics
If , what is the value of x?
10
5
9
1
2
9
Example Question #3 : Other Squaring / Square Roots
If x and y are integers and xy + y2 is even, which of the following statements must be true?
I. 3y is odd
II. y/2 is an integer
III. xy is even
I, II, & III
I only
II only
I & II
In order for the original statement to be true, the and
terms must be either both odd or both even. Looking at each of the statements individually,
I. States that is odd, but only odd values multiplied by 3 are odd. If
was an even number, the result would be even. But
can be either odd or even, depending on what
equals. Thus this statement COULD be true but does not HAVE to be true.
II. States that is an integer, and since only even numbers are cleanly divided by 2 (odd values result in a fraction) this ensures that
is even. However,
can also be odd, so this is a statement that COULD be true but does not HAVE to be true.
III. For exponents, only the base value determines whether it is even or odd - it does not indicate the value of y at all. Only even numbers raised to any power are even, thus, this ensures that is even. But
can be odd as well, so this statement COULD be true but does not HAVE to be true.
An example of two integers that will work violate conditions II and III is and
.
, and even number.
is not an integer.
is not even.
Furthermore, any combination of 2 even integers will make the original statement true, and violate the Statement I.
Example Question #1043 : Sat Mathematics
How many integers from 20 to 80, inclusive, are NOT the square of another integer?
First list all the integers between 20 and 80 that are squares of another integer:
52 = 25
62 = 36
72 = 49
82 = 64
In total, there are 61 integers from 20 to 80, inclusive. 61 – 4 = 57
Example Question #2 : How To Find The Square Of An Integer
Let the universal set be the set of all positive integers.
Let be the set of all multiples of 3; let
be the set of all multiples of 7; let
be the set of all perfect square integers. Which of the following statements is true of 243?
Note: means "the complement of
", etc.
, so 243 is divisible by 3.
.
, so 243 is not divisible by 7.
- that is,
.
, 243 is not a perfect square integer.
- that is,
.
Since 243 is an element of ,
, and
, it is an element of their intersection. The correct choice is that
Example Question #162 : Arithmetic
Consider the inequality:
Which of the following could be a value of ?
There is no possible value for
Notice how is the greatest value. This often means that
is negative as
when
is odd and
when
is even.
Let us examine the first choice,
This can only be true of a negative value that lies between zero and one.
Example Question #1 : How To Find The Square Of An Integer
In the equation above, if is a positive integer, what is the value of
?
Begin by squaring both sides of the equation:
Now solve for y:
Note that must be positive as defined in the original question. In this case,
must be 12.
Example Question #531 : Arithmetic
Simplify. Assume all integers are positive real numbers.
There are two ways to solve this problem.
First, leave the question in decimal form.
Second, put your question in fraction form.
Example Question #1 : How To Square A Decimal
If all real values of lie between 0 and 1, which of the following is always greater than 1?
If is greater than 0, then adding 1 to
will make it greater than 1. Taking a number between 0 and 1 to a power results in a smaller number.
Example Question #2 : How To Square A Decimal
Evaluate:
0.082
0.064
0.64
0.00064
0.0064
0.00064
0.0064
0.08 * 0.08
First square 8:
8 * 8 = 64
Then move the decimal four places to the left:
0.0064
Certified Tutor
All PSAT Math Resources
