Quantitative Aptitude - Arithmetic Ability Questions

Mahanath works 2 times as fast as Sahay. If Sahay can complete a job alone in 21 days, then in how many days can they together finish the job?

A bookseller bought 500 text books for  20,000. He wanted to sell them at a profit so that he get 50 books free. At what profit percent should he sell them?

A box weighs 8.5 kg when full of sand and weighs 5.5 kg when it is half filled with sand . Weight of the empty box is

In each of the following questions two equations I and II are given. Solve both the equations and give answer:
$$\begin{gathered} I. x2+2x-195=0 \\ II. y2+30y+225=0 \end{gathered}$$

If the radius of a circumscribed circle in an equilateral triangle is 14 cm. Then what will be the radius (in cm) of the inscribed circle?

In the given figure, PQ is a diameter of the semicircle PABQ and O is its center. AOB = 64 deg. BP cuts AQ at X. What is the value (in deg) of AXP?

If a = 73, b = 74 and c = 75, then what is the value of a3 + b3 + c3 – 3abc?

The marked price of an article is Rs. 5000. But due to a special festive offer a certain percent of discount is declared. Mr. X availed this oppurtunity and bought the article at reduced price. He then sold it at Rs. 5000 and thereby made a profit of 11 1/9%. The percentage of discount allowed was?