Quantitative Aptitude - Arithmetic Ability Questions

In a class of 56 students there are 28 girls. The average weight of these girls is 46 kg and average weight of the full class is 51 kgs. What is the average weight of the boys of the class?

50 litre mixture of water and alcohol contains 10% alcohol. How much more alcohol must be added to make the strength of alcohol 40% in the new mixture?

A boy in a train notices that he can count 31 telephone posts in 60 seconds. the distance between two posts is 60 meters. Calculate the speed of the train?

The centroid of an equilateral triangle ABC is G. If AB is 6 cms, the length of AG is

If a+bab=21 ,  then the value of (a-b) is

The orthocentre of an obtuse­angled triangle lies

From a point P on a level ground , the angle of elevation to the top of the tower is 30° . If the tower is 100m high , the distance of point P from the foot of the tower is ( Take √3 = 1.73)

Select the odd word/letters/number/number pair from the given alternatives.