Quantitative Aptitude - Arithmetic Ability Questions

If the time increases by 7 years, then simple interest increases by Rs 8400 on a sum of Rs 6000. What is the rate (in percentage) of interest per annum?

If [2(4x/5 - 3/4)]/3 - 5/3 = -1/6, then the value of x is?

Point Q(-2,b) is the midpoint of segment EF. Co-ordinates of E are (-7,-6) and F are (a,0). What is the value of a and b?

What is the value of (1 + cotA)2 + (1 -­ cotA)2?

In ΔDEF measure of angle E is 90 deg. If sinD = 15/17, and DE = 4cm, then what is the length (in cm) of side EF?

The area of a circle is 616 sq.m. Find its diameter.

If x = 313- 3-13, then 3x2 + 9xis equal to

Three solid spheres have their radii r1, r2 and r3. The spheres are melted to form a solid sphere of bigger radius. Then the radius of the new sphere is