Quantitative Aptitude - Arithmetic Ability Questions

Consider two-digit numbers which remain the same when the digits interchange their positions. What is the average of such two-digit numbers?

The radius of a sphere is 6 cm. It is melted and drawn into a wire of radius 0.2 cm. The length of the wire is

Find the area (in sq.cm) of a semi-circle of radius 7 cm

What must be the length (in cm) of the diagonal of a rectangle if its area and breadth are 60 cm² and 5 cm respectively?

Two students appeared for an examination. One of them secured 16 marks more than the other and his marks were 75% of the sum of their marks. The marks obtained by them are

If w : 0.80 :: 9 : 6, w = ?

The average monthly salary of 19 members of a group is Rs. 16000. If one more members whose monthly salary is Rs. 20000 has joined the group, then the average salary of the group is

Josna takes 4 hrs 30 min in walking a distance and riding back to some place where she started. She could walk both ways in 5 hrs 40 min. The time taken by her to ride back both ways is