Quantitative Aptitude - Arithmetic Ability Questions

If 1-aa3+9 = 19 - a1-a3, then what is the value of a?

A person borrows some money for 4 years at the rate of simple interest. If the ratio of principal and total interest is 5 : 1, then what is the rate ( in percentage) of interest?

A trader buys 800 kgs of tomatoes for Rs 7200. 10% tomatoes are damaged in transportaion. At what rate (Rs/Kg) should he sell the rest to earn 30% profit?

What is the length of the arc whose central angle is 30° and radius of the circle is 21 cm?

What will be the acute angle between the hour-hand and the minute -hand at 2:13 p.m?

The area of the largest triangle that can be inscribed in a semicircle of radius 6m is

Select the related number from the given alternatives.
0.02 : 0.002 :: 1/3 : ?

If 2x + (9/x) = 9, then what is the minimum value of x2+1x2 = ?