Quantitative Aptitude - Arithmetic Ability Questions

If x - y = -6 and x + y = 16, then x2- y2 is?

The area of a square is 40.5 cm². Find the length of its diagonal (in cm).

Mr. Kapur purchased two toy cycles for Rs 750 each. He sold these cycles, gaining 6% on one and losing 4% on the other. The gain or loss percent in the whole transaction is

A spaceship travels at 810 km/hr. How many metres does it travel in 1/5th of a second?

50 litre mixture of water and alcohol contains 10% alcohol. How much more alcohol must be added to make the strength of alcohol 40% in the new mixture?

P, Q and R together can make a table in 40 minutes. P and Q together can make it in 60 minutes. How much time (in minutes) will R alone take to make the table?

What should be the missing digit so that the number 347_547 becomes exactly divisible by 11?

The length of the diagonal and the breadth of a rectangle are 26 cm and 10 cm respectively. Find its perimeter (in cm).