GMAT Math : Arithmetic
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Example Questions
Example Question #12 : Calculating Percents
A number is divided by 6; its decimal point is then moved to the left one place. This is the same as taking what percent of the number?
Dividing the number by 6 is the same as multiplying it by 
To find its percent equivalent, multiply by 100:
The correct choice is 
Example Question #13 : Calculating Percents
If 10 percent of 
This is simply a matter of breaking down the problem. 10 percent of 
25 percent of (half of y) is 25 percent of 
Now we have these two being equal, so
or
giving
Finally,
Example Question #11 : Calculating Percents
The Republic of Fredonia uses an unusual currency system. 14 fluts are equal to 1 glut, and 16 gluts are equal to 1 blut.
A hat that cost 14 gluts 10 fluts yesterday now costs an even 1 blut. To the nearest tenth of a percent, what percent markup does this represent?
This can be most easily done by looking at the current and former price in fluts.
The current price is 1 blut, or 
Yesterday's price was 14 gluts 10 fluts, or 
This represents a markup of 
Example Question #12 : Percents
Gary weighs 20 percent more than Harry who's weight is 80 percent of James' weight. If James weighs 172 pounds, how much would Gary weigh if he lost 12 pounds? (Rounded to the nearest pound).
If James weighs 172 pounds, and Harry weighs 80% of that, then
he is 120% Harry's weight 
he would weigh 153.12 or 153 pounds.
Example Question #12 : Calculating Percents
The price of an item is decreased by 10%, then by 20%, then by 30%. This is equivalent to doing what?
Decreasing the price by 60%.
Decreasing the price by 50.4%
Decreasing the price by 49.6%
Decreasing the price by 50%.
Decreasing the price by 40%
Decreasing the price by 49.6%
Decreasing a price by 10%, then by 20%, then by 30% is equivalent to taking 90% of a price, then taking 80% of that, then taking 70% of that. That, in turn, is equivalent to multiplying the price by 0.90, then by 0.80, then by 0.70.
For simplicity's sake, assume the initial price was $100. Then we can calculate the final price as follows:
The final price is $50.40, so we essentially discounted the price by $49.60, which is 49.6%.
Example Question #12 : Calculating Percents
What is 15 percent of 80?
This word problem can be written as
Simplifying this, we get
Example Question #1649 : Problem Solving Questions
Refer to the above figure. Each of the squares is of equal area. What percent of the figure is green?
Out of the twenty squares, three are green; this is 
Example Question #14 : Percents
A number is multiplied by one-sixth; the product is divided by one-seventh; that quotient is multiplied by seven-tenths. What percent of the original number is the final result?
The best way to do this is to start with 100 and to calculate the final result, which will be the correct answer.
The final result will be as follows:
The final number will be 
Example Question #97 : Arithmetic
A number is divided by four; the quotient is divided by three; that quotient is multiplied by five; and the decimal point in that product is moved to the left one place. What percent of the original number is that final result?
The best way to solve this is to start with the original number being 100. The result is the percent.
The result of subsequent divisions by four and three, multiplication by five, and shifting the decimal point one place left - or division by ten - is
or, equivalently,
This can be calculated as
So for any number at which we start out, the final result is 
Example Question #21 : Calculating Percents
The above is an annual income tax table for single persons in a given state.
Mr. McKenzie earned a salary of $2,270 per month until August 1, when he received a 10% raise. He also received a $2,000 bonus and $511 in interest.
Assuming that there was no additional income, calculate Mr. McKenzie's income tax to the nearest dollar.
None
Mr. McKenzie earned $2,270 per month for seven months, earning a total of
His raise on August 1 was 10%, making his new salary
He earned this over the remaining five months, earning
Add these and the bonus and interest to get
This places Mr. McKenzie in the $20-40,000 income bracket, so he will pay $50 plus 0.8% of earnings above $20,000. This will be
The correct response is $137.
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