Quantitative Aptitude - Arithmetic Ability Questions

A 150 m long train, travelling at 54 km/h, crosses a platform in 42 seconds. What is the length of the platform?

Iftan 450=cot∅, then the value of ∅, in radians is 

A sum of Rs 1200 amounts to Rs 1740 in 3 years at simple interest. If rate of interest is increased by 3%, then what will be the new amount (in Rs)?

For what sum will the simple interest at R% for 2 years will be R?

If the time increases by 7 years, then simple interest increases by Rs 8400 on a sum of Rs 6000. What is the rate (in percentage) of interest per annum?

If 2 shirts are offered free on purchase of 3 shirts priced Rs 600 each, then what will be the effective discount on each shirt?

What is the measure of an exterior angle of a regular polygon of 10 sides?

A's salary was decreased by 50% and subsequently increased by 50%. How much percent does he lose?