Quantitative Aptitude - Arithmetic Ability Questions

X, Y and Z can do a piece of work in 30,40 and 50 days respectively. All three of them began the work together but Y left 4 days before completion of the work. In how many days was the work completed?

What is the remainder, when 4x4 +10x3-20x2+90 is divided by (x+2) ?

Starting with 8000 workers, the company increases the number of workers by 5%, 10% and 20% at the end of first, second and third year respectively. The number of workers in the fourth yearwas

If cot A = n/(n + 1) and cot B = 1/(2n + 1), then what is the value of cot (A + B)?

A spherical lead ball of radius 6 cm is melted and small lead balls of radius 3 mm are made. The total number of possible small lead balls is

Two cars travel from city A to city B at a speed of 30 and 48 km/hr respectively. If one car takes 3 hours lesser time than the other car for the journey, then the distance between City A and City B is

A solid sphere of diameter 7 cm is cut into two equal halves. What will be the increase (in cm2) in the total surface area ?

The sum of a non-zero number and 4 times its reciprocal is 17/2. What is the number?