All GRE Math Resources
Example Questions
Example Question #10 : Decimal Operations
find 0.7^{2}
0.49
0.0049
4.9
0.049
49
0.49
0.7 * 0.7 = 0.49
Trick: do the numbers without the decimals (7*7)
49; move the decimal of the answer the total number of spaces per each number (one for each 0.7)
0.49
Example Question #1 : How To Multiply Decimals
There are 3,500 people in group A and 5,000 people in group B:
Car Type |
% in Group A Who Own |
% in Group B Who Own |
Motorbike |
4 |
9 |
Sedan |
35 |
25 |
Minivan |
22 |
15 |
Van |
9 |
12 |
Coupe |
3 |
6 |
The number of people in group B who own a minivan is how much greater or less than the number of people in group A who own a minivan?
50 fewer
15 more
30 more
30 fewer
20 fewer
20 fewer
In this question, simply take the percentage of each group that owns a minivan and compare the values. For minivans we look at the middle row which we recognize as a percent that must be converted to a decimal. Acknowledge that there's a different number of people between the groups A and B:
Group B: 0.15(5000) = 750
Group A: 0.22(3500) = 770
750 – 770 = –20; thus, group B has 20 fewer people who own minivans than group A.
Example Question #2 : How To Multiply Decimals
Given that , which best describes the relationship between , , and ?
We must recognize that if x and y are both between 0 and 1, then they must be fractions (decimals). To determine their relationships, we can substitute values for x and y. Let's have and (because y must be greater than x).
If x and y are both between 0 and 1, then xy is also between 0 and 1 (though smaller than either x or y individually).
The value of (xy)^{2} will be less than (xy), since squaring any number between 0 and 1 gives a smaller result.
Finally, is largest, since dividing a larger number by a smaller one gives a result greater than 1.
Note that the substituted values for x and y were purely hypothetical; any values that satisfy the given inequality could be used.
Example Question #1 : How To Multiply Decimals
You bought a dozen eggs marked at and received change from . What is the percent of sales tax?
Set the equation up as
Solve for , which equals
or
Therefore the percent sales tax is: