Quantitative Aptitude - Arithmetic Ability Questions

On a machine there is 10% trade discount on the marked price of Rs 2,50,000. But the machine is sold at Rs 2,16,000 after giving a cash discount. How much is this cash discount (in %)?

The standard deviation of the set {10, 11, 9, 11, 9} is

If 56 × 75 × 60 × 84 × 210 = 2p × 3q × 5r × 7s, then what is the value of [(p + q)/s] + r?

The sum of the ages of father and a son presently is 70 years. After 10 years, the son's age is exactly half that of the father. What are their ages now?

A and B have to type a book together containing 120 pages. A takes 9 hrs to type 36 pages and B takes 5 hrs to type 40 pages. A typed first 60 pages alone and the last 60 pages were typed by A and B together. How much time (in hours) will be taken to type the complete book?

If 35% of A's income is equal to 25% of B's income, then the ratio of A's income to B's income is

Value of (cos 53° - sin 37°) is

If x and y are natural numbers such that x + y = 2017, then what is the value of (– 1)x+ (– 1)y?