Quantitative Aptitude - Arithmetic Ability Questions

A merchant changed his trade discount from 25% to 15%. This would increase selling price by

A car travels a certain distance at 34 km/h and comes back at 66 km/h. What is the average speed for total journey?

What is the largest 4 digit number which is exactly divisible by 81?

Anil can do a piece of work in 14 days which Rohit can do in 21 days. They worked together for few days after which Anil left. If Rohit worked alone for 3 days, find the total number of days it took to complete the whole work.

If x = 4aba+b, then what is the value of x+2ax-2a+x+2bx-2b ?

What is the reflection of the point (3,-5) in the origin?

[sinA/(1 + cosA)] + [(1 + cosA)/sinA] is equal to

If cosx.cosy + sinx.siny = -1 then cosx + cosy is