Quantitative Aptitude - Arithmetic Ability Questions

The mean of marks secured by 65 students in division A of class X is 54, 30 students of division B is 50 and that of 55 students of division C is 48. Find the mean of marks of the students of three divisions of Class X.

Simple interest on a sum for six months at 5% per annum is Rs 65.5.What is the value (in Rs) of sum ?

A racing car going at an average speed of 108 km/hr takes 15 minutes to complete a lap on a racing track. By how much should it increase its speed (inkm/hr) to complete the lap in 12 minutes?

P alone can do a piece of work in 8 days and Q alone can do the same work in 10 days. In how many days will both together complete the same work?

In an army selection process, the ratio of selected to unselected candidates was 4:1. If 90 less had applied and 20 less selected, the ratio of selected to unselected would have been 5:1. How many candidates had applied for the process?

If a3- b3= 91 and a - b = 1, then what is the value of ab?

The cross­section of a canal is in the shape of an isosceles trapezium which is 3 m wide at the bottom and 5 m wide at the top. If the depth of the canal is 2 m and it is 110 m long, what is the maximum capacity of this canal? (Take π = 22/7)

If a shopkeeper sells an item at Rs 4200 which is marked as Rs 4800, then what is the discount (in %) that he is offering?