Admission Tests Admission Tests Certifications GMAT-QUANTITIVE Questions & Answers

• Question 681:

  During a sale, the price of a pair of shoes is marked down 10% from the regular price. After the sale ends, the price goes back to the original price. What is the percent of increase to the nearest percent from the sale price back to the regular price for the shoes?

  A. 9%

  B. 10%

  C. 11%

  D. 15%

  E. 90%

  Correct Answer: C

  Suppose that the shoes cost $10. $10 – 10% = 10 – 1 = $9. When the shoes are marked back up, 10% of $9 is only 90 cents. Therefore, the markup must be greater than 10%. $1/$9 = 11 1/9 %, or about 11%.

• Question 682:

  Given the area of the three squares, find the perimeter of ABC.

  

  A. 12

  B. 12.5

  C. 19.5

  D. 20

  E. 25

  Correct Answer: A

  The length of one side of a square is equal to the square root of the area of the square. Since the area of the squares is 9, 16, and 25, the lengths of the sides of the squares are 3, 4, and 5, respectively. The

  triangle is formed by the sides of the three squares; therefore, the perimeter, or distance around the triangle, is 3 + 4 + 5 = 12.

• Question 683:

  If it takes Steve 6 hours to tile a floor and Cheryl 4 hours to tile the same floor, how long would it take both Steve and Cheryl to tile the floor if they worked together?

  A. 2 hours 12 minutes

  B. 2 hours 24 minutes

  C. 3 hours

  D. 3 hours 12 minutes

  E. 10 hours

  Correct Answer: B

  Let x = the part of the floor that can be tiled in 1 hour. Since Steve can tile a floor in 6 hours, he can tile 1/6 of the floor in 1 hour. Since Cheryl can tile the same floor in 4 hours, she can tile 1/4 of the floor in 1 hour. Use the equation 1/6 + 1/4 = 1/x, where 1/x represents the part of the floor they can tile in an hour together. Multiply each term by the LCD = 12x. 12x × 1/6 + 12 x × 1/4 = 12 x × 1/x. The equation simplifies to 2x + 3x = 12.5x = 12. Divide each side by 5 to get x = 12/5 =2.4 hours. Since 0.4 times 60 minutes equals 24 minutes, the final answer is 2 hours 24 minutes.

• Question 684:

  How many liters of a 40% iodine solution need to be mixed with 35 liters of a 20% iodine solution to create a 35% iodine solution?

  A. 35

  B. 49

  C. 100

  D. 105

  E. 140

  Correct Answer: D

  Let x = the number of liters of the 40% solution. Use the equation 0.40x + 0.20(35) = 0.35 (x + 35) to show

  the two amounts mixed equal the 35% solution.

  Solve the equation: 0.40x + 0.20(35) = 0.35(x + 35)

  Multiply both sides by 100 in order to work with more compatible numbers:

  40x + 20(35) = 35(x + 35)

  40x + 700 = 35x + 1,225

  Subtract 700 on both sides: 40x + 700 ?700 = 35x + 1,225 ?700 Subtract 35x from both sides 40x ?35x =

  35x ?35x + 525

  Divide both sides by 5:5x/5 = 525/5

  x = 105 liters of 35% iodine solution

• Question 685:

  Which of the following has the smallest numerical value?

  A. 23 x 22

  B. 26

  C. 25 x 21

  D. (22)3

  E. 23 x 33

  Correct Answer: A

  Using the rules for exponents, choice a simplifies to 25 and choices b, c, and d simplify to 26 = 64. Choice e becomes 27 ?81, which is obviously much larger than 64.

• Question 686:

  What is the final balance of a bank account after two years if the starting balance is $1,000 at an annual rate of 5%, using simple interest? Assume no other money was withdrawn or deposited.

  A. $50

  B. $100

  C. $1,050

  D. $1,100

  E. $1,150

  Correct Answer: D

  This problem can be solved by using the simple interest formula: interest = principal ?rate ?time. Remember to change the interest rate to a decimal before using it in the formula. I = (1,000) (0.05) (2) = $100. Since $100 was made in interest, the total in the bank account is $1,000 + $100 = $1,100.

• Question 687:

  A certain jacket was marked down 20% the first week and another 20% the next week. What percent of the regular price was the final cost of the jacket after the two markdowns?

  A. 30%

  B. 36%

  C. 40%

  D. 60%

  E. 64%

  Correct Answer: E

  To make this problem easier, assume the initial cost of the jacket was $100. The first markdown of 20% would save you $20, bringing the cost of the jacket to $80. For the second markdown, you should be finding 20% of $80, the new cost of the jacket. 20% of 80 = 0.20 × 80 = 16. If you save $16 the second time, the final cost of the jacket is 80 – 16 = $64. Since the initial cost was $100, $64 is 64% of this price.

• Question 688:

  If 20 typists can type 48 letters in 20 minutes, then how many letters will 30 typists working at the same rate complete in 1 hour?

  A. 63

  B. 72

  C. 144

  D. 216

  E. 400

  Correct Answer: D

  First calculate the number of letters completed by 30 typists in 20 minutes. Let x = the number of letters typed by 30 typists and set up the proportion typists/letters = 20/48 = 30/x. Cross-multiply to get 20x = 1,440. Divide both sides by 20 and get x = 72. Since 20 minutes is one-third of an hour, multiply 72 ?3 = 216 to get the total letters for one hour.

• Question 689:

  Celeste worked for h hours each day for d consecutive days. If she earns $9.50 per hour, what is the total amount she earned?

  A. 9.50/d + h

  B. 9.50 + d + h

  C. 9.50 + dh

  D. 9.50h + d

  E. 9.50dh

  Correct Answer: E

  Suppose Celeste worked for 8 hours each day for 5 consecutive days. Her total pay would be found by

  finding her total hours (8 × 5 = 40) and then multiplying 40 by her pay per hour ($9.50).

  Since you are only multiplying to solve the problem, the expression is 9.50 × d × h or 9.50dh.

• Question 690:

  Which of the following measures could form the sides of a triangle? I) 3, 3, 5 II) 6, 6, 12 III) 1, 2, 3

  A. I only

  B. II only

  C. III only

  D. I and II only

  E. II and III only

  Correct Answer: A

  The sum of the measures of the two shorter sides of a triangle must be greater than the longest side. Since 3 + 3 > 5, statement I works. Since 6 + 6 = 12 and 1 + 2 = 3, they do not form the sides of the triangle. The answer is statement I only.