Quantitative Aptitude - Arithmetic Ability Questions

To travel 648 km, an Express train takes 12 hours more than Rajdhani. If however, the speed of the Express train is doubled, it takes 6 hours less than Rajdhani. The speed of Rajdhani is _____.

A racing car going at an average speed of 108 km/hr takes 15 minutes to complete a lap on a racing track. By how much should it increase its speed (inkm/hr) to complete the lap in 12 minutes?

If (x + y):(x - y) = 11:1, find value of (5x + 3y)/(x - 2y).

PQR is a right angled triangle in which PQ = QR. If the hypotenuse of the triangle is 20 cm, then what is the area (in cm2) of the triangle PQR?

If x + y = 13 and x2 + y2 = 89, then find xy is

If L : M = 3 : 5 and M : N = 2 : 3, then N : L = ?

If a = 299, b = 298, c = 297 then the value of 2a3 + 2b3 + 2c3 - 6abc is

What will be the net discount percentage of three successive discounts of 20%, 10% and 30%?