Quantitative Aptitude - Arithmetic Ability Questions

If 4x - 7y = 3 and 2x - y = 9, then x - y is.

In ∆XYZ measure of angle Y is 90 deg. If sinX = 4/5, and XY = 6cm, then what is the length (in cm) of side YZ?

When a discount of 20% is given on a monthly train pass, the profit is 44%. If the discount is 29%, then the profit is _____.

If (x+a) is the H.C.F of 2x2+5x-12 and x2+x-12 then find the value of a.

If ab+ba = -1, then the value of a2b-b2a is

If xy = -18 and x2+ y2= 85, then find the value of (x + y).

The ratio of present ages of R and S is 6:7. Before 12 years the ratio of their ages was 9:11. What is R's present age (in years)?

A sells a watch to B and makes a loss of 12%. B makes a profit of 12.5% by selling the watch to C. If A sells the watch to B at the cost of which C purchased it, then the percentage of loss or profit of A will be,