All PSAT Math Resources
Example Questions
Example Question #6 : How To Evaluate A Fraction
Factor out 7 from the numerator:
This simplifies to 7.
Example Question #1281 : Psat Mathematics
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 #1282 : Psat Mathematics
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 #1283 : Psat Mathematics
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 #261 : Gre Quantitative Reasoning
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:
Example Question #261 : Gre Quantitative Reasoning
Simplify:
Begin by simplifying the numerator and the denominator.
Numerator
has a common denominator of . Therefore, we have:
Denominator
has a common denominator of . Therefore, we have:
Now, reconstructing our fraction, we have:
To make this division work, you multiply the numerator by the reciprocal of the denominator:
Example Question #35 : Algebraic Fractions
Simplify:
None of the other answer choices are correct.
Recall that dividing is equivalent multiplying by the reciprocal. Therefore, ((x - 4) / (1 / 2)) / (1 / (x + 4)) = ((x - 4) * 2) * (x + 4) / 1.
Let's simplify this further:
(2x – 8) * (x + 4) = 2x2 – 8x + 8x – 32 = 2x2 – 32
Example Question #262 : Gre Quantitative Reasoning
Solve for :
Begin by isolating the variables:
Now, the common denominator of the variable terms is . The common denominator of the constant values is . Thus, you can rewrite your equation:
Simplify:
Cross-multiply:
Simplify:
Finally, solve for :
Example Question #1 : How To Simplify A Fraction
The expression
A negative exponent in the numerator of a fraction can be rewritten with a positive exponent in the denominator. The same is true for a negative exponent in the denominator. Thus, .
When is multiplied by , the numerators and denominators cancel out, and you are left with 1.
Example Question #2 : How To Simplify A Fraction
Two two-digit numbers, and , sum to produce a three-digit number in which the second digit is equal to . The addition is represented below. (Note that the variables are used to represent individual digits; no multiplication is taking place).
What is ?
Another way to represent this question is:
In the one's column, and add to produce a number with a two in the one's place. In the ten's column, we can see that a one must carry in order to get a digit in the hundred's place. Together, we can combine these deductions to see that the sum of and must be twelve (a one in the ten's place and a two in the one's place).
In the one's column:
The one carries to the ten's column.
In the ten's column:
The three goes into the answer and the one carries to the hundred's place. The final answer is 132. From this, we can see that because .
Using this information, we can solve for .
You can check your answer by returning to the original addition and plugging in the values of and .
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