Quantitative Aptitude - Arithmetic Ability Questions

P, Q and R alone can complete a work in 12, 15 and 20 days respectively. In how many days will they together complete the same work?

If each median of an equilateral triangle has a length of 12cm. Then what will be the value of in-radius (in cm) of the equilateral triangle?

If x3 – y3 = 81 and x – y = 3, then what is the value of x2 + y2?

If sec 300° = x, then value of x is

Mohit sells a table at a profit of 25%. If he reduces its selling price by Rs 240, then he suffers a loss of 5%. What was the initial selling price (in Rs) of the table?

If a number is decreased by 10%, it becomes 54. To make it 72, it should be increased by

15% of a number, when added to 30% of another, gives 24% of the sum of the two numbers. The bigger number is 4 more than the smaller one. What are the numbers?

In the figure, B and C are the centres of the two circles. ADE is the common tangent to the two circles. If the ratio of the radius of both the circles is 3:5 and AC= 40, then what is the value of DE?