Quantitative Aptitude - Arithmetic Ability Questions

Of the four numbers whose average is 91, the first is 3/10 times the sum of other three. The first number is:

A train is moving at the speed of 72km/hr. How many seconds will it take to cover a distance of 1400 m ?

A bus runs at 50 kmph. If the speed is increased by 10 kmph, it will cover 20 km more in the same time. Find the actual distance covered?

The price of an article is cut by 36%, to restore to its original value, the new price must be increased by

60% of P = 50% of Q and Q = x% of P. What is the value of x?

If xy = -18 and x2+ y2= 85, then find the value of (x + y).

Two numbers are 35% and 50% lesser than a third number. By how much percent is the second number to be enhanced to make it equal to the first number? 

A is twice as good as B and together they finish a piece of work in 16 days. The number of days taken by A alone to finish the work is