Quantitative Aptitude - Arithmetic Ability Questions

If the value of √30  is approximately 5.477, then what is the approximate value of 56 ?

Incentre of Δ ABC is I. ∠ABC = 90° and ∠ACB = 70°. ∠AIC is

A boat is sailing towards a lighthouse of height 20√3 m at a certain speed. The angle of elevation of the top of the lighthouse changes from 30° to 60° in 10 seconds. What is the time taken (in seconds) by the boat to reach the lighthouse from its initial position?

The sum of three numbers is 252. If the first number is thrice the second and third number is two-third of the first, then the second number is

A train of length, 245 metres, takes 20 seconds to cross a 355 metres long bridge. How much time (in seconds) will the train take to cross a 390 metres long platform?

A bus is running at a speed of 90 kmph. What distance will it cover in 20 seconds?

What is the value of xy if x - y = 3 and x2+y2=15?