All SAT II Math I Resources
Example Questions
Example Question #5 : Sequences
What is the next number in the sequence?
The first number is multiplied by three
.
Then it is divide by two
.
The following is multiplied by three
then divided by two
.
That makes the next step to multiply by three which gives us
.
Example Question #62 : Mathematical Relationships
An arithmetic sequence begins as follows:
Give the tenth term of this sequence.
Rewrite the first term in fraction form: .
The sequence now begins
,...
Rewrite the terms with their least common denominator, which is :
The common difference of the sequence is the difference of the second and first terms, which is
.
The rule for term of an arithmetic sequence, given first term and common difference , is
;
Setting , , and , we can find the tenth term by evaluating the expression:
,
the correct response.
Example Question #6 : Sequences
A geometric sequence begins as follows:
Express the next term of the sequence in simplest radical form.
Using the Product of Radicals principle, we can simplify the first two terms of the sequence as follows:
The common ratio of a geometric sequence is the quotient of the second term and the first:
Multiply the second term by the common ratio to obtain the third term:
Example Question #64 : Mathematical Relationships
The second and third terms of a geometric sequence are and , respectively. Give the first term.
The common ratio of a geometric sequence is the quotient of the third term and the second:
Multiplying numerator and denominator by , this becomes
The second term of the sequence is equal to the first term multiplied by the common ratio:
.
so equivalently:
Substituting:
,
the correct response.
Example Question #1 : Sequences
A geometric sequence begins as follows:
Give the next term of the sequence.
None of the other choices gives the correct response.
The common ratio of a geometric sequence is the quotient of the second term and the first:
Simplify this common ratio by multiplying both numerator and denominator by :
Multiply the second term by the common ratio to obtain the third term:
Example Question #66 : Mathematical Relationships
A geometric sequence has as its first and third terms and 24, respectively. Which of the following could be its second term?
None of these
Let be the common ratio of the geometric sequence. Then
and
Therefore,
,
and
Setting :
.
Substituting for and , either
.
The second term can be either or , the former of which is a choice.
Example Question #61 : Mathematical Relationships
The first and third terms of a geometric sequence comprising only positive elements are and , respectively. In simplest form, which of the following is its second term?
None of these
Let be the common ratio of the geometric sequence. Then
and
Therefore,
,
Setting , and applying the Quotient of Radicals Rule:
Taking the square root of both sides:
Substituting, and applying the Product of Radicals Rule:
Since all elements of the sequence are positive, .
Example Question #1 : Other Mathematical Relationships
Multiply in modulo 6:
In modulo 6 arithmetic, a number is congruent to the reainder of its division by 6.
Therefore, since and ,
.
The correct response is 0.
Example Question #1 : Other Mathematical Relationships
Which is an example of a set that is not closed under addition?
The set
All of the sets given in the other responses are closed under addition.
The set of all negative integers
The set of all integers between 1 and 10 inclusive
The set of all positive even integers
The set of all integers between 1 and 10 inclusive
A set is closed under addition if and only if the sum of any two (not necessarily distinct) elements of the set is also an element of the set.
is closed under addition, since
The set of all negative integers is closed under addition, since any two negative integers can be added to yield a third negative integer.
The set of all positive even integers is closed under addition, since any two positive even integers can be added to yield a third positive even integer.
The remaining set is the set of all integers between 1 and 10 inclusive. It is not closed under addition, as can be seen by this counterexample:
but
Example Question #2 : Other Mathematical Relationships
varies directly as the square root of .
If then . To the nearest tenth, calculate if .
varies directly as , which means that for some constant of variation ,
We can write this relationship alternatively as
where the initial conditions can be substituted on the left side and final conditions, on the right. We will be solving for in the equation