Quantitative Aptitude - Arithmetic Ability Questions

Among three numbers, the first is twice the second and thrice the third. If the average of three numbers is 396, then what is the difference between the first and the third number?

A non-zero number is greater than 7 times its reciprocal by 9.3. What is the number?

What is the sum of the first 12 terms of an arithmetic progression if the first term is 3 and last term is 47?

Working 10 hours a day, Aman can complete a piece of work in 18 days. How many hours a day should he work so as to finish the work in 15 days?

If a3 + b 3 = 35 and ab = 6, then what is the value of a + b?

Find two numbers such that their mean proportion is 8 and third proportion is 64.

If 5/2 - (6/5)(x - 15/2) = -x/5, then what is the value of x?

If (1 -­ cosA)/(1 + cosA) = x, then the value of x is