Quantitative Aptitude - Arithmetic Ability Questions

What least value must be assigned to '*' so that the numbers 451 *  603 is exactly divisible by 9?

If secA - tanA = x, then the value of x is

What approximate value should come in place of the question mark (?) in the following equation (Note: You are not expected to calculate the exact value)?

[(7.99)2–(13.001)2+(4.01)3]2=?

A rice trader buys 20 quintals of rice for Rs 8,580. However, 22% rice is lost in transportation. At what rate should he sell to earn 20% profit?

The sum of the ages of brother and sister at present is 21. Five years ago the product of their ages was 28. What is the age of the brother and the sister?

Two bikers A and B start and ride at 75 km/hr and 60 km/hr respectively towards each other. They meet after 20 minutes. How far (in km) were they from each other when they started?

A regular triangular pyramid is cut by 2 planes which are parallel to its base. The planes trisects the altitude of the pyramid. Volume of top, middle and bottom part is V1, V2 and V3 respectively. What is the value of V1 :V2 : V3?

What is the difference (in Rs) in Compound interest earned in 1 year on a sum of Rs 10,000 at 40% per annum compounded quarterly and annually?