Quantitative Aptitude - Arithmetic Ability Questions

If a + b = 4 and ab = 3, then what is the value of a3 + b3?

An 80 litre mixture of water and acid contains 20% acid. How much acid should be added to make the acid 60% in the new mixture?

The effective annual rate of interest corresponding to a nominal rate of 15% per annum payable half-yearly is

A batsman makes a score of 111 runs in the 10th match and thus increases his average runs per match by 5. What will be his average after the 10th match?

The alcohol and water in a mixture are in the ratio of 7 : 8 respectively. If 11 litre water is added to it, then the ratio of alcohol and water in the new mixture becomes 3 : 5. What is the total quantity (in litres) of the alcohol in the new mixture?

How many natural numbers are there between √261 and √45109?

Rakesh goes on a trip on his motor­cycle and rides for 368 kms. If he rides for 5 hours at a speed of 49 km/hr, at what speed he travels for the remaining 3 hours of the journey?

A vendor buys 6 bananas for Rs 25 and sells them at 3 for Rs 20. What is his profit percentage?