- C When a Discrete Quantitative question has variables in the question and
in the choices, consider plugging in numbers. In the question, the new price
of the shirt, z, depends on the original price, x, and the percent increase, y, so
choose values for x and y, and let those values determine z. Let x = 100 and y =
25. Thus the new price of the shirt is $125. Plug the values you chose for x and
y into the choices, and see which yields you $125. - D The formula for calculating profit is p = r – c, where p = profit, r = revenue,
and c = cost. The revenue for the car is $20,000. You are told that the profit was
25% of the purchase price. You can express this algebraically as r – c = 0.25c.
Now plug in $20,000 for r: 20,000 – c = 0.25c. Solve for c:
20,000 = 1.25c
20,0001.25 = c
c = 16,000 - 75 Since you are dealing with a percent question with no amounts given,
plug in values for the unknowns. Let x = 100. If y is 50% greater than x, then
y = 100 + 0. 5(10 0) = 150. You thus want to determine what percent 150 is
of 200. Use the formula for calculating percents: wholepart × 100.
(15 0/2 0 0) × 100 = 75.
Quantitative Comparison Questions
- C To arrive at a value for Quantity A, use the percent formula: wholepart = 100 p. In
this case, 90 is the part and 50 is the whole, so Quantity A is equivalent to
90
50 ×^ 100. To arrive at a value for Quantity B, use the percent change formula
(difference/original) × 100. The difference between the two numbers is 90.
The original number is 50. Plugging these values into the formula, you arrive
at^9050 × 100. Column B and Column A have the same value. - A Option 1: Solve it intuitively.
The price of the stock after a y percent increase is more than the original
price of the stock. For a z percent decrease to bring the stock value back
to its original price, z% of the price in 1993 must be the same as y% of the
price in 1993. Since the value in 1993 is greater than the value in 1992, the
whole that z% is taken from is bigger, which means a smaller piece of that
whole is needed to arrive at y% of 1992. If you need a smaller piece, that
means that z, as a percentage of 1993, is smaller than y, as a percentage of
1992. The answer is A.
Option 2: Plug in numbers.
Since you are dealing with percents, choose $100 for x and 25 for y. Use
these values to determine what value for z would bring the price back to
$100. If y = 25, then the price in 1992 will be 125. Now solve for z: 25 is
what percent of 125? Use the percent formula: wholepart × 100 = 12525 × 100 = 20%.
Thus when y = 25, z = 20. Column A is greater. - C Avoid calculating! Notice that the columns have very similar digits, but
different place values. Write each column in decimal format and see how the
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