Quantitative Aptitude - Arithmetic Ability Questions

Factors of 36 - 

The average weight of P, Q and R is 47 kg. If the average weight of P and Q be 32.5 kg and that of Q and R be 48.5 kg, then what is the weight of Q (in kgs)?

If a+bab=21 ,  then the value of (a-b) is

At what percentage above the cost price must an article be marked so as to gain 33% after allowing a customer a discount of 5%?

A kite is flying in the sky. The length of string between a point on the ground and kite is 420 m. The angle of elevation of string with the ground is 30 deg. Assuming that there is no slack in the string, then what is the height (in metres) of the kite?

If 25% of an electricity bill is deducted, Rs 1788 is still to be paid. How much was the bill?

If x = 1 + √2 + √3, then the value of x2-2x-4=0

Slope of the line AB is -4/3. Co-ordinates of points A and B are (x, -5) and (-5, 3) respectively. What is the value of x?