Quantitative Aptitude - Arithmetic Ability Questions

If cos 135° = x, then the value of x is

If cos2x + cos4x = 1, then tan2x + tan4x =

From a point P, the angle of elevation of a tower is such that its tangent is 3/4. On walking 560 metres towards the tower the tangent of the angle of elevation of the tower becomes 4/3. What is the height (in metres) of the tower?

If a3 + 3a2 + 9a = 1, then what is the value of a3 + (3/a)?

A boat covers a distance of 14 km upstream and 16 km downstream in 9 hours. It covers a distance of 12 km upstream and 40 km downstream in 11hours. What is the speed (in km/hr) of the boat in still water?

If 1/√(1 -­ sin2A) = x, then the value of x is

If sum of Rs.1000 amount to Rs.1331 in 3 years, compounded annually. Then, find the rate of interest per annum?