Quantitative Aptitude - Arithmetic Ability Questions

Determine the value of  'a' which satisfies the equation 9a + 40a = 41a

At what rate of compound interest per annum will a sum of Rs 20000 become Rs 23328 in 2 years?

A man is running at the speed of 20 km/hr. What is time (in seconds) taken by man to cover one round of a circular garden of radius 350 metres?

Cost price of a calculator is Rs 495. If the profit percentage is 40%, then what is the value (in Rs) of profit?

The sum of the digits of a 2-digit number is 11. If we add 45 to the number, the new number obtained is a number formed by interchange of the digits. What is the number?

Tom's father is thrice as old as Tom. 10 years ago Tom's father's age was 7 times his age. What is Tom's current age? 

Three bottles of equal capacity have mixture of milk and water in ratio 5 : 7, 7 : 9 and 2 : 1 respectively. These three bottles are emptied into a large bottle. What is the percentage of milk in the new mixture?

A jar contains a blend of a fruit juice and water in the ratio 5 : x. When 1 litre of water is added to 4 litres of the blend the ratio of fruit juice to water becomes 1 : 1. What is the value of x?