Quantitative Aptitude - Arithmetic Ability Questions

There are 90 coins, comprising of 5 and 10 paisa coins. The value of all the coins is Rs. 7. How many 5 paisa coins are there?

A can paint a house in 45 days and B can do it in 15 days. Along with C, they did the job in 5 days only. Then, C alone can do the job in how many days?

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?

The expression 52n –23n has a factor?

Three categories of employees get wages in the ratio of 1 : 2 : 3. If they get increments of 5%, 10% and 15% respectively, what will be the new ratio of their wages?

What is the value of 1+aa1/2+a-1/2-a1/2+a-1/21+a+a-1/2 ?

If x + (1/x) = 2, then what is the value of x21 + (1/x1331)?

If 2 T-shirts are offered free on purchase of 5 T-shirts, what is the effective discount (in %) on each T-shirt?