All PSAT Math Resources
Example Questions
Example Question #2 : How To Evaluate A Fraction
For this question, the following trigonometric identities apply:
,
Simplify:
To begin a problem like this, you must first convert everything to and alone. This way, you can begin to cancel and combine to its most simplified form.
Since and , we insert those identities into the equation as follows.
From here we combine the numerator and denominators of each fraction together to easily see what we can combine and cancel.
Since there is a in the numerator and the denominator, we can cancel them as they divide to equal 1. All we have left is , the answer.
Example Question #3 : How To Evaluate A Fraction
If 3x = 12, y/4 = 10, and 4z = 9, what is the value of (10xyz)/xy?
4 1/2
10
360
160
22 1/2
22 1/2
Solve for the variables, the plug into formula.
x = 12/3 = 4
y = 10 * 4 = 40
z= 9/4 = 2 1/4
10xyz = 3600
Xy = 160
3600/160 = 22 1/2
Example Question #4 : How To Evaluate A Fraction
If , , and , find the value of .
In order to solve , we must first find the values of , , and using the initial equations provided. Starting with :
Then:
Finally:
With the values of , , and in hand, we can solve the final equation:
Example Question #5 : How To Evaluate A Fraction
If and , then which of the following is equal to ?
In order to solve , first substitute the values of and provided in the problem:
Find the Least Common Multiple (LCM) of the fractional terms in the denominator and find the equivalent fractions with the same common denominator:
Finally, in order to divide by a fraction, we must multiply by the reciprocal of the fraction:
Example Question #6 : How To Evaluate A Fraction
Find the value of if and .
In order to solve for , first substitute into the equation for :
Then, find the Least Common Multiple (LCM) of the two fractions and generate equivalent fractions with the same denominator:
Finally, simplify the equation:
Example Question #1 : How To Evaluate A Fraction
Factor out 7 from the numerator:
This simplifies to 7.
Example Question #11 : How To Evaluate A Fraction
If pizzas cost dollars and sodas cost dollars, what is the cost of pizzas and sodas in terms of and ?
If 10 pizzas cost x dollars, then each pizza costs x/10. Similarly, each soda costs y/6. We can add the pizzas and sodas together by finding a common denominator:
Example Question #12 : How To Evaluate A Fraction
According the pie chart, the degree measure of the sector representing the number of workers spending 5 to 9 years in the same role is how much greater in the construction industry chart than in the financial industry chart?
Since the values in the pie charts are currently in terms of percentages (/100), we must convert them to degrees (/360, since within a circle) to solve the question. The "5 to 9 years" portion for the financial and construction industries are 18 and 25 percent, respectively. As such, we can cross-multiply both:
18/100 = x/360
x = 65 degrees
25/100 = y/360
y = 90 degrees
Subtract: 90 – 65 = 25 degrees
Alternatively, we could first subtract the percentages (25 – 18 = 7), then convert the 7% to degree form via the same method of cross-multiplication.
Example Question #871 : Algebra
6 contestants have an equal chance of winning a game. One contestant is disqualified, so now the 5 remaining contestants again have an equal chance of winning. How much more likely is a contestant to win after the disqualification?
When there are 6 people playing, each contestant has a 1/6 chance of winning. After the disqualification, the remaining contestants have a 1/5 chance of winning.
1/5 – 1/6 = 6/30 – 5/30 = 1/30.
Example Question #872 : Algebra
Simplify:
Begin by simplifying the numerator.
has a common denominator of . Therefore, we can rewrite it as:
Now, in our original problem this is really is:
When you divide by a fraction, you really multiply by the reciprocal: