Quantitative Aptitude - Arithmetic Ability Questions

The average age of 40 students of a class is 16 years. If the average age of 24 students is 15.5 years and that of the 15 students is 16 2⁄3 years, then the age of 40th student is

The surface area of a sphere is 1386 cm2.  Find its diameter (in cm)

Find the radius of the circle if the length of its arc is 33 cm whose corresponding central angle is 90° ?

The slopes of two lines are 1 and √3. What is the angle between these two lines?

What is the area (in sq cm) of a regular hexagon of side 9 cm?

The areas of two similar triangles ΔXYZ and ΔPQR are 100 sq cms and 25 sq cms respectively. If PQ = 4 cm then what is the length of XY (in cm)?

A Village lost 12% of its goats in a flood and 5% of remainder died from diseases. If the number left now is 8360. What was the orignal number before the flood?

Find the Greatest Common Factor of 280 and 144.