Quantitative Aptitude - Arithmetic Ability Questions

Find the sum of interior angles of a dodecagon?

Two numbers are 40% and 50% lesser than a third number. By how much percent is the second number to be enhanced to make it equal to the first number?

Working together P, Q and R reap a field in 6 days. If P can do it alone in 10 days and Q in 24 days, in how many days will R alone be able to reap the field?

A, B and C can do a job working alone in 12, 16 and 24 days respectively. In how many days they can do the job if they worked together?

At least one diagonal bisects the other in a _____.

A solid cube is cut into 27 identical cubes. What is the percentage increase in the total surface area?

What is the difference of the factors of the expression x2 + (1/x2) – 6?

Expanded and simplification of (x + 3)(x - 1) will be equal to