Quantitative Aptitude - Arithmetic Ability Questions

A can do a work in 15 days and B in 20 days. If they work on it together for 5 days, then what fraction of work is left?

Sum of three consecutive integers is 51 . The middle one is:

Find the number that is as much greater than 49 as is less than 95.

What is the value of Sin 30° + 2 Cos 30° ?

If a and b are the roots of the equation Px2 – Qx + R = 0, then what is the value of (1/a2) + (1/b2) + (a/b) + (b/a)?

How many times in a week does both the hands of the clock will coincide with each other?

At 24% discount the selling price of a washing machine is Rs 38000, what is the selling price if the discount is 40%?

What is the effective discount on two successive discounts of 20% and 25%?