Quantitative Aptitude - Arithmetic Ability Questions

Which one does not belong to the group?

What are the co­ordinates of the mid point of the segment joining points C(5,­-2) and D(­-1,8).

What is the distance between the points (4,­-8) and (­-2,0)?

Find the sum of the measures all the exterior angles of a decagon.

If 3P/7 = 4Q/11, then what is the ratio of P and Q respectively?

Some girls can do a piece of work in 18 days. In how much time (in days) two times the number of such girls will complete thrice of the work?

A chord of length 60 cm is at a distance of 16 cm from the centre of a circle. What is the radius (in cm) of the circle?

Pipe A can fill an empty cistern in 4 hours while along with Pipe B it can fill it up in 3 hours. Only Pipe A is turned on for an hour after which Pipe B is also turned on. How much total time will it take to fill up the cistern?