If (x2 + 1/x2) = 102, then (x - 1/x) is :

B. 10

X and Y together complete a work in 8 hours. If X alone can complete it in 12 hours than Y alone can complete it in

A. 24 HOURS
Posted in:  Time & Work -  Aptitude -  Mathematics

Some machines complete the work in 4 days. But if 4 other machines are included in this work, then the job shall be completed in 2 days. If capacities of all machines are same, then in how many days 2 machines can complete this work ?

B. 8 DAYS
Posted in:  Time & Work -  Aptitude -  Mathematics

If α and β are the roots of the equation
$x^2 - 9x + 8 = 0$ (α > β) then find the value of
$α^2 - β^2$.

C. 65
Posted in:  Quadratic Equations -  Algebra -  Mathematics

The solution of the system of simultaneous linear equations
4x - 3y = 7 and 7x + 5y = 2 is :

D. X = 1, Y = -1
Posted in:  Linear Equations -  Algebra -  Mathematics