General Quantitative Aptitude Basics Questions and Answers

Question 1

A shopkeeper sells an item for $150 after marking it up by 25% on the cost price. Due to low sales, he decides to offer a discount. What is the maximum percentage discount he can offer on the marked price to avoid making a loss?

Accepted Answer

20%

Answer

First, find the cost price (CP). The marked price ($150) is 125% of the CP. So, CP = $150 / 1.25 = $120. To avoid a loss, the selling price must not be less than the cost price ($120). The maximum discount is the difference between the marked price and the cost price, which is $150 - $120 = $30. The discount percentage is calculated on the marked price: ($30 / $150) * 100 = 20%.

Question 2

Working alone, machine A can complete a task in 6 hours. Working alone, machine B can complete the same task in 9 hours. If both machines start working together, but machine A breaks down after 2 hours, how many more hours will it take for machine B to complete the rest of the task alone?

Accepted Answer

4 hours

Answer

Machine A's 1-hour work rate is 1/6 of the task. Machine B's 1-hour work rate is 1/9 of the task. Together, their combined rate is 1/6 + 1/9 = 5/18 of the task per hour. In 2 hours, they complete 2 * (5/18) = 5/9 of the task. The remaining work is 1 - 5/9 = 4/9 of the task. Since only machine B is working, the time required is (Remaining Work) / (B's Rate) = (4/9) / (1/9) = 4 hours.

Question 3

The average age of a group of 30 students is 14 years. When the teacher's age is included, the average age of the group increases to 15 years. What is the teacher's age?

Accepted Answer

45 years

Answer

The total age of the 30 students is 30 * 14 = 420 years. When the teacher is included, there are 31 people in the group, and the new average age is 15. The new total age is 31 * 15 = 465 years. The teacher's age is the difference between the new total age and the original total age: 465 - 420 = 45 years.

Question 4

A train traveling at a constant speed of 90 km/hr crosses a stationary pole in 8 seconds. What is the length of the train?

Accepted Answer

200 meters

Answer

First, convert the speed from km/hr to m/s. Speed = 90 km/hr * (1000 m/km) / (3600 s/hr) = 25 m/s. The distance the train travels to cross a pole is equal to its own length. Using the formula Distance = Speed × Time, the length of the train is 25 m/s * 8 s = 200 meters.

Question 5

The salaries of two individuals, Alex and Ben, are in the ratio of 4:5. If Alex's salary is increased by 10% and Ben's salary is increased by 20%, what is the new ratio of their salaries?

Accepted Answer

11:15

Answer

Let Alex's original salary be 4x and Ben's be 5x. After a 10% increase, Alex's new salary is 4x * 1.10 = 4.4x. After a 20% increase, Ben's new salary is 5x * 1.20 = 6.0x. The new ratio of their salaries is 4.4x : 6.0x. To remove the decimals, multiply both sides by 10, which gives 44:60. This ratio can be simplified by dividing both sides by their greatest common divisor, 4, resulting in the new ratio of 11:15.

General Practice Test

General Practice Test

General Quantitative Aptitude Basics Questions and Answers