Quantitative Aptitude - Arithmetic Ability Questions

What number should be added to each of the numbers 55, 100, 65 and 116, so that the resulting numbers are in continued proportion?

If 3x^2 + ax + 4 is perectly divisible by x - 5, then the value of a is :

If ax + by = 1 and bx + ay = 2aba2+b2 then x2+y2a2+b2 is equal to

Find the value of 532+108

If a2+1a2 = 38, then find the value of a-1a?

What least value which should be added to 1812 to make it divisible by 7, 11 and 14?

If  2x+14x = 1, then the value of  x2+164x2is

In ∆ ABC, the height CD intersects AB at D. The midpoints of AB and BC are P and Q respectively. If AD = 8 cm and CD = 6 cm, then the length of PQ is?