All PSAT Math Resources
Example Questions
Example Question #813 : Arithmetic
Which set represents all the single-digits integers (0-9) that are either prime, a perfect square, or found in the number 68?
The prime digits are 2, 3, 5, and 7.
The perfect square digits are 0, 1, 4, and 9.
The only digits not represent in these two groups are 6 and 8, which are, coincidentally, found in the number 68.
Example Question #1701 : Sat Mathematics
If four different integers are selected, one from each of the following sets, what is the greater sum that these four integers could have?
W = {4, 6, 9, 10}
X = {4, 5, 8, 10}
Y = {3, 6, 7, 11}
Z = {5, 8, 10, 11}
42
41
38
40
39
38
By observing each of these sets, we can easily determine the largest number in each; however, the problem is asking for us to find the greatest possible sum if we select four different integers, one from each set. The largest number is 11. We will either select this number from set Y or set Z.
We will select set
Y for the 11
because the next larger number in set
Z is 10, which is greater than the next largest number is set Y, 7.
We can use set Z for 10.
Because the 10 has already been selected, choosing the integer from W and X should be easy because 9 is the next largest integer from set W
and
8 is the next largest integer from set X.
11 + 10 + 9 + 8 = 38
Example Question #171 : Integers
A team has a win-loss ratio of . If the team wins six games in a row, the win-loss ratio will now be . How many losses did the team have initially?
If a team's ratio of wins to losses increases from to by winning six games, they must have 12 wins initially and 3 losses.
Example Question #1 : How To Find The Missing Number In A Set
Find the missing number in the following set:
The rule is as follows: add 2 to the previous number then multiply times 2.
The answer is (16 + 2) * 2 = 36.
Example Question #351 : Arithmetic
If the average of Set is , what is the average of Set ?
We know the average of Set A is 5. Therefore:
Now let's solve for :
We can now plug this value of into Set B and solve for the average:
Set B = {0, 2, 4}
The average of Set B is 2.
Example Question #1 : How To Find Consecutive Integers
The sum of three consecutive even integers is 108. What is the largest number?
42
34
40
38
36
38
Three consecutive even integers can be represented by x, x+2, x+4. The sum is 3x+6, which is equal to 108. Thus, 3x+6=108. Solving for x yields x=34. However, the question asks for the largest number, which is x+4 or 38. Please make sure to answer what the question asks for!
You could have also plugged in the answer choices. If you plugged in 38 as the largest number, then the previous even integer would be 36 and the next previous even integer 34. The sum of 34, 36, and 38 yields 108.
Example Question #121 : Integers
The sum of three consecutive even integers equals 72. What is the product of these integers?
10560
12144
13800
17472
13728
13728
Let us call x the smallest integer. Because the next two numbers are consecutive even integers, we can call represent them as x + 2 and x + 4. We are told the sum of x, x+2, and x+4 is equal to 72.
x + (x + 2) + (x + 4) = 72
3x + 6 = 72
3x = 66
x = 22.
This means that the integers are 22, 24, and 26. The question asks us for the product of these numbers, which is 22(24)(26) = 13728.
The answer is 13728.
Example Question #2 : How To Find Consecutive Integers
Four consecutive integers have a mean of 9.5. What is the largest of these integers?
9
11
13
12
8
11
Four consecutive integers could be represented as n, n+1, n+2, n+3
Therefore, by saying that they have a mean of 9.5, we mean to say:
(n + n+1 + n+2 + n+ 3)/4 = 9.5
(4n + 6)/4 = 9.5 → 4n + 6 = 38 → 4n = 32 → n = 8
Therefore, the largest value is n + 3, or 11.
Example Question #1 : How To Find Consecutive Integers
The sum of four consecutive odd integers is equal to 96. How many of the integers are prime?
4
1
2
3
0
1
Let x be the smallest of the four integers. We are told that the integers are consecutive odd integers. Because odd integers are separated by two, each consecutive odd integer is two larger than the one before it. Thus, we can let x + 2 represent the second integer, x + 4 represent the third, and x + 6 represent the fourth. The sum of the four integers equals 96, so we can write the following equation:
x + (x + 2) + (x + 4) + (x + 6) = 96
Combine x terms.
4x + 2 + 4 + 6 = 96
Combine constants on the left side.
4x + 12 = 96
Subtract 12 from both sides.
4x = 84
Divide both sides by 4.
x = 21
This means the smallest integer is 21. The other integers are therefore 23, 25, and 27.
The question asks us how many of the four integers are prime. A prime number is divisible only by itself and one. Among the four integers, only 23 is prime. The number 21 is divisible by 3 and 7; the number 25 is divisible by 5; and 27 is divisible by 3 and 9. Thus, 23 is the only number from the integers that is prime. There is only one prime integer.
The answer is 1.
Example Question #1 : Sequences
The sum of three consecutive integers is 60. Find the smallest of these three integers.
Assume the three consecutive integers equal , , and . The sum of these three integers is 60. Thus,