Quantitative Aptitude - Arithmetic Ability Questions

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

A shopkeeper marks up his wares by 125% and offers 25% discount. What will be the selling price if the cost price (in Rs) is Rs 640?

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?

A does 30% of a work in 30 days. He then calls in B and they together finish the remaining work in 20 days. How long B alone would take to do the whole work?

Mansukh can do a piece of work in 10 hours. If he is joined by Jayanti who is 50% more efficient, in what time will they together finish the work?

If a shop keeper marks his goods for a certain amount so as to get 25% gain after allowing a discount of 20%, then his marked price is

If the edge of a cube is increased by 3 cm, the volume will increase by 657 cub.cm. What then is the original length of each edge of the cube?

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?