All ISEE Upper Level Quantitative Resources
Example Questions
Example Question #1 : Other Factors / Multiples
Which of the following is the prime factorization of 333?
333 cannot be factorized further
To find the prime factorization, break the number down as a product of factors, then keep doing this until all of the factors are prime.
Example Question #2 : Other Factors / Multiples
Give the prime factorization of 91.
91 is a prime number.
Both are prime factors so this is the prime factorization.
Example Question #3 : Other Factors / Multiples
How many factors does 40 have?
40 has as its factors 1, 2, 4, 5, 8, 10, 20, and 40 - a total of eight factors.
Example Question #11 : Numbers And Operations
What is the sum of all of the factors of 27?
27 has four factors:
Their sum is .
Example Question #5 : Other Factors / Multiples
Add all of the factors of 30.
The factors of 30 are 1, 2, 3, 5, 6, 10, 15, and 30. Their sum is
.
Example Question #13 : Numbers And Operations
Which is the greater quantity?
(a) The number of factors of 169
(b) The number of factors of 121
It is impossible to tell from the information given
(a) and (b) are equal
(b) is greater
(a) is greater
(a) and (b) are equal
Each number has only three factors. 121 has 1, 11, and 121 as factors; 169 has 1, 13, and 169 as factors. The answer is that the quantities are equal.
Example Question #6 : How To Factor A Number
Which is the greater quantity?
(a) The number of factors of 15
(b) The number of factors of 17
(a) is greater.
It is impossible to tell from the information given.
(b) is greater.
(a) and (b) are equal.
(a) is greater.
(a) 15 has four factors, 1, 3, 5, and 15.
(b) 17, as a prime, has two factors, 1 and 17.
Therefore, (a) is greater.
Example Question #9 : How To Factor A Number
Which is the greater quantity?
(a) The product of the integers between and inclusive
(b) The sum of the integers between and inclusive
(b) is greater.
It is impossible to tell from the information given.
(a) and (b) are equal.
(a) is greater.
(a) and (b) are equal.
The quanitites are equal, as both can be demonstrated to be equal to .
(a) One of the integers in the given range is , so one of the factors will be , making the product .
(b) The sum of the numbers will be:
Example Question #5 : Other Factors / Multiples
Which is the greater quantity?
(a) The sum of the factors of
(b) The sum of the factors of
It is impossible to tell from the information given.
(a) is greater.
(a) and (b) are equal.
(b) is greater.
(b) is greater.
(a) The factors of are Their sum is
.
(b) The factors of are Their sum is
.
(b) is greater.
Example Question #12 : Numbers And Operations
Which is the greater quantity?
(a) The sum of all of the two-digit even numbers
(b) 2,500
(b) is greater
(a) and (b) are equal
(a) is greater
It is impossible to tell from the information given
(b) is greater
The sum of the integers from to is equal to . We take advantage of the fact that the sum of the even numbers from 10 to 98 is equal to twice the sum of the integers from 5 to 49, as seen here: