Quantitative Aptitude - Arithmetic Ability Questions

In the following question, four number pairs are given. The number on left side of (–) is related to the number on the right side of (–) with some Logic/Rule/Relation. Three are similar on basis of same Logic/Rule/Relation. Select the odd one out from the given alternatives.

Find the LCM of 12, 16, 20 and 24.

What is the sum of the first 17 terms of an arithmetic progression if the first term is -20 and last term is 28?

What is the value of [2 sin (45 + θ) sin (45 – θ)]/cos 2θ?

What are the co­-ordinates of the mid point of the segment joining points C(0,­-3) and D(8,5)?

Two donkeys are standing 400 meters apart. First donkey can run at a speed of 3 m/sec and the second can run at 2 m/sec. If two donkeys run towards each other after how much time (in sec) will they bump into each other?

4 hrs after a goods train passed a station, another train travelling at a speed of 60 km/hr following that goods train passed through that station. If after passing the station the train overtakes the goods train in 8 hours. What is the speed of the goods train?

A 600 metres long train is running at the speed of 81 km/hr. If it crosses a platform in 40 seconds, then what is the length of the platform (in metres)?