Quantitative Aptitude - Arithmetic Ability Questions

Find the value of  x3 - y3, if x - y = 4 and xy = 12.

The circumference of a circle is 110 cm. Find its radius (in cm).

A train 110 metres long is running with a speed of 60 kmph . In what time will it pass a man who is running at 6 kmph in the direction opposite to that in which the train is going ?

A, B and C can finish a job working alone in 20, 30 and 60 days respectively. They all work together for 1 day, then A and B quit. How many days C working alone will take to finish the remaining part of the job?

Five men or ten women can complete a job in 20 days. In how many days can 3 men and 4 women complete it?

1/3 part of a certain journey is covered with the speed of 25 km/hr, 1/2 part of the journey is covered with the speed of 45 km/hr and the remaining part covered with the speed of 37.5 km/hr. What is the average speed (in km/hr) for the whole journey?

The mean of 10 observations is 17. One more observation is included and the new mean becomes 16. The 11th observation is

The sum of three consecutive even numbers is 42. Find the middle number.