Quantitative Aptitude - Arithmetic Ability Questions

What should be added to 8(3x - ­4y) to obtain 18x ­- 18y?

What is the value of (1/2) Sec 30° + √2 Tan 60°?

What are the roots of the quadratic equation: x2 + 3x ­- 154 = 0

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

Two cars travel from city A to city B at a speed of 60 and 108 km/hr respectively. If one car takes 2 hours lesser time than the other car for the journey, then the distance between City A and City B?

A 800 metres long train is running at the speed of 90 km/hr. If it crosses a bridge in 50 seconds, then what is the length (in metres) of the bridge?

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

Six year ago Parvez’s age was same as the present age of Manish. If the present age of Parvez is one-fourth more than that of Manish's present age, then in how many years will Parvez’s age become double of Manish’s present age?