Quantitative Aptitude - Arithmetic Ability Questions

The reciprocal of the sum of the reciprocals of 2/9 and 7/10 is

To cover a distance of 333 km in 2 hours by a car, what should be the average speed of the car (in meter/second)?

If a taxi going at 40 km/hr takes 25 minutes to travel a certain distance, by how much should it increase its speed (in km/hr) to travel the same distance in 20 minutes?

The percent profit made when an article is sold for Rs. 78 is twice as much as when it is sold for Rs. 69, the cost price of the article is?

What is the value of the expression a3 - 5 + 2816a, when a = 2?

Selling price of an article is Rs 494 and discount of 5% is offered. What is the marked price (in Rs)?

If three numbers are in the ratio 2 : 3 : 5 and the twice their sum is 100. Find the square of the largest of the three numbers.

If a:b = 3:8, find the value of (5a ­ 3b)/(2a + b).