Quantitative Aptitude - Arithmetic Ability Questions

The compound interest earned in two years at 15% per annum is Rs 20640. What is the sum invested (in Rs)?

39 is 5.2% of?

If P/Q = R/S = T/U = 3/4 is (4P + 5R + 7T) : (3Q + 4S + 7U)?

An equilateral triangle ABC is inscribed in a circle of radius 20√3.
What is the length of the side of the triangle?

If 27N4 is divisible by 11, then what is the value of N?

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)?

What is the length of the side of an equilateral triangle, if its area is 64√3 sq cm?

The circumference of a circle is equal to the perimeter of an equilateral triangle. If the radius of the circle is 7 cm what is the length of the side of the equilateral triangle?