Quantitative Aptitude - Arithmetic Ability Questions

If x3 – y3 = 81 and x – y = 3, then what is the value of x2 + y2?

If p and q are the roots of the equation x2 –15x + r = 0 and p –q = 1, then what is the value of r ?

If a = √2 + 1, b = √2 - 1 then the value of 1a+1+1b+1 ?

If A's salary is 40% less than that of B, then how much percent is B's salary more than that of A?

A does 30% of a work in 30 days. He then calls in B and they together finish the remaining work in 20 days. How long B alone would take to do the whole work?

If each median of an equilateral triangle has a length of 12cm. Then what will be the value of in-radius (in cm) of the equilateral triangle?

∆PQR is right angled at Q. If sinP = 12/13, then what is the value of tanR?

A and B have to type a book together containing 120 pages. A takes 9 hrs to type 36 pages and B takes 5 hrs to type 40 pages. A typed first 60 pages alone and the last 60 pages were typed by A and B together. How much time (in hours) will be taken to type the complete book?