All HSPT Math Resources
Example Questions
Example Question #62 : How To Do Other Word Problems
A number of balls are placed in a box, each with an integer from 1 to 10 inclusive. Each composite number is represented by one ball; each other number, two balls. Give the probability that a ball randomly drawn from this box will be odd.
In the range of 1 to 10, the composite numbers - the numbers with at least one factor other than 1 and itself - are 4, 6, 8, 9, and 10. Therefore, there are five composite numbers represented by two balls each, and five noncomposite numbers (1, 2, 3, 5, 7) represnted by 1 ball each. The total number of balls is
Among the odd numbers, 1, 3, 5, and 7 are represented by one ball each; 9 is represented by two, for a total of 6 balls out of 15. This makes the probability of drawing an odd number
Example Question #63 : How To Do Other Word Problems
Mr. and Mrs. Johnson are hosting a party with their six children. The above shows their two tables along with their seats.
Mr. and Mrs. Johnson want to sit across from each other at the same table. How many seating arrangements meet this requirement?
The following choices need to be made:
First, the decision must be made as to the table at which the Johnsons will sit. There are two choices.
Next, the decision must be made as to which seats the Johnsons will occupy at that table. There are two choices - the "north-and-south" seats and the "east-and-west" seats.
Third, the decision must be made which one will sit where; there are two choices now.
Fourth, the decision must be made as to how the six children will be seated - this will be
.
By the multiplication principle, the number of seating arrangements with the Johnsons sitting across from each other will be
Example Question #541 : Hspt Mathematics
How many different ways can a single digit be written in the box to form an integer divisible by 11?
Five
Two
One
None
None
An integer is divisible by 11 if and only if its alternating digit sum is divisible by 11. If we let be the missing digit, then the alternating digit sum is
Through trial and error, we see that no value of from 0 to 10 makes this a multple of 11. This makes none the correct choice.
Example Question #102 : Word Problems
In a given college:
Everyone who likes "The Walking Dead" likes "Boardwalk Empire".
Everyone who dislikes "The Sopranos" likes "Deadwood".
Nobody likes both "Boardwalk Empire" and "The Sopranos".
Philip, a student at this college, likes "The Walking Dead". Which of the following does he also like - "The Sopranos" or "Deadwood"?
Both "The Sopranos" and "Deadwood"
"The Sopranos", but not "Deadwood"
Neither "The Sopranos" nor "Deadwood"
"Deadwood", but not "The Sopranos"
"Deadwood", but not "The Sopranos"
Let , , , and represent the set of students who like "The Walking Dead", "Boardwalk Empire", "The Sopranos", and "Deadwood", repsectively.
Everyone who likes "The Walking Dead" likes "Boardwalk Empire", so .
Everyone who dislikes "The Sopranos" likes "Deadwood", so .
Nobody likes both "Boardwalk Empire" and "The Sopranos", so and have no elements in common - they are disoint sets. One way of saying this is that everyone who likes "Boardwalk Empire" dislikes "The Sopranos" - that is, .
These statements can be put together as follows:
We can represent Philip as . Philip likes "The Walking Dead", so it follows that
, which means he does not like "The Sopranos",
and
, which means he likes "Deadwood".
Example Question #544 : Problem Solving
In a given high school:
Every student who likes Diddy also likes Prince.
Every student who likes Weezer also likes Bruce Springsteen.
No student likes both Prince and Bruce Springsteen.
Jerry is a student at this high school who likes Weezer. Which of the following does he also like - Diddy or Prince?
Neither Diddy nor Prince
Both Diddy and Prince
Prince, but not Diddy
Diddy, but not Prince
Neither Diddy nor Prince
Let , , , and represent students who like Diddy, Prince, Weezer, and Bruce Springsteen, respectively.
Every student who likes Diddy also likes Prince, so .
Every student who likes Weezer also likes Bruce Springsteen, so
No student likes both Prince and Bruce Springsteen, so and have no elements in common - they are disjoint sets.
A Venn diagram for this scenario is below:
Note that since Jerry ("j") is an element of , he cannot be an element of or . Therefore, he does not like Diddy or Prince.
Example Question #545 : Problem Solving
In state X, the fine for speeding is $75 plus $4 for each mile per hour over the limit that the person was driving. If the speed limit is and the driver's speed is , then which of the following formulas could be used to calculate the driver's fine?
The number of miles per hour over the limit is the difference of the number of miles per hour the driver was going and the speed limit - this is . The fine is $75 plus $4 times this difference:
Example Question #107 : Word Problems
Let the universal set be the set of all people.
Let , , and be the set of all people who like The Rolling Stones, Bob Seger, and Alanis Morissette, respectively. If represents John, then how would you represent the statement:
as an English-language sentence?
John likes Bob Seger, but he dislikes both The Rolling Stones and Alanis Morissette.
John likes Bob Seger, but he dislikes The Rolling Stones, Alanis Morissette, or both.
John likes The Rolling Stones and Alanis Morissette, but he dislikes Bob Seger.
John likes either The Rolling Stones, Alanis Morissette, or both, but he dislikes Bob Seger.
John likes The Rolling Stones and Alanis Morissette, but he dislikes Bob Seger.
is the intersection of two sets, and . itself is the intersection of , the set of persons who like The Rolling Stones, and , the set of persons who like Alanis Morissette. is the set of persons who like Bob Seger, so , the complement of , is the set of persons not in - that is, persons who dislike Bob Seger.
Therefore, anyone in the set likes The Rolling Stones, likes Alanis Morissette, and dislikes Bob Seger. The correct choice is "John likes The Rolling Stones and Alanis Morissette, but he dislikes Bob Seger."
Example Question #71 : How To Do Other Word Problems
Mr. And Mrs. Jackson have invited six guests to dinner, including Mr. Jackson's brother Steve and Mrs. Jackson's brother Jim. Steve and Jim do not like each other, so it is desired that they not sit in adjacent seats. How many arrangements are possible that conform to this specification?
First, we note that the total number of seating arrangements for eight people is
The number of arrangements that would have Steve and Jim in adjacent seats would be calculated as follows:
The number of ways to choose two adjacent seats is eight: 1-2, 2-3, and so forth up to 8-1. Multiply this by 2, since each choice has two different orders for Steve and Jim. Multiply this by
,
the number of ways the remaining six persons can be seated. This makes
seating arrangements with Steve and Jim together. Since this is not desired, subtract this from the total number of arrangements:
This is the number of arrangments without Steve and Jim together, and it is the correct choice.
Example Question #72 : How To Do Other Word Problems
Let the universal set be the set of positive integers. Let be the set of prime numbers and be the set of odd numbers. Which of the following is in the set ?
By DeMorgan's Law,
That is, the complement of the union of two sets is the intersection of their complements.
Also, the complement of a complement of a set is the set itself, so and . Therefore,
.
Consequently, we are looking for a number that falls in the intersection of and . The number must be both prime and odd. 2 and 4 are eliminated for being even. 1 is not considered a prime number, having only one factor. 3, which has only two factors, 1 and 3, is prime, and is the correct choice.
Example Question #541 : Hspt Mathematics
Fill in the missing digit to form a number that is divisible by 44:
A number that is divisible by 44 must also be divisible by all factors of 44.
One factor is 4. The number is divisible by 4 if the last two digits form a number itself divisible by 4. Since the last two digits are "12", which is divisible by 4, we know the number to be divisible by 4 regardless of the digit chosen.
Another factor is 11. The number is divisible by 11 if and only of the alternating sum has an absolute value divisible by 11. If is the missing digit, then
.
We can set each of the choices equal to and see which one works:
Only in the case is the alternating sum divisible by 11, so this is the correct choice.