Quantitative Aptitude - Arithmetic Ability Questions

A and B are positive integers. If A + B + AB = 65, then what is the difference between A and B (A, B ≤ 15)?

What is the value of 143 + 163 + 183 + ... + 303?

What is the value of 4600+540+1280+250+36 ?

If x + y + z = 0, then what is the value of (3y2 + x2 + z2 )/(2y2 – xz)?

If P = 7 + 4√3 and PQ = 1, then what is the value of 1/P2 + 1/Q2?

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

x, y and z are real numbers. If x3 + y3 + z3 = 13, x + y + z = 1 and xyz = 1, then what is the value of xy + yz + zx?

If (a + b)/c = 6/5 and (b + c)/a = 9/2, then what is the value of (a + c)/b?