Quantitative Aptitude - Arithmetic Ability Questions

What is the value of √[(1 ­- cosA)/(1 + cosA)]?

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

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

The mean of 10 observations is 17. One more observation is included and the new mean becomes 16. The 11th observation is

The ratio of present ages of Ramita and Satyajit is 9:7. After 9 years the ratio of their ages will be 5:4. What is Ramita's present age?

One-third of Poojitha's age three years ago plus one-half of her age two years from now is twenty years. How old is she now?

If secA = x, then the value of x is

What is the value of x4+y4 when the value of x3+y3=8 and x+y=2 ?