Factors

Recall also that any perfect square has an odd number of factors. If there is an even number of even factors, that means there must be an odd number of odd factors. An odd number of odds added together will be odd. So the sum of the factors of the number will be even + odd = odd.

Refer to MGMAT CAT 5 Q 35. { revise before exam}

Perimeter

When we calculate the perimeter of a figure we should concentrate on the boundary layers not the inner ones.

See Ex MGMAT 4 , Q 12

Benchmarking

Benchmarking is an important technique - It helps to solve irritating decimal questions. Practice some of these kinds. It is definitely going to help you on the exam.

MEAN, Median

For any evenly spaced set, the mean of the set is always equal to the median. A set of consecutive integers is an example of an evenly spaced set. If we find the mean of this set, we will be able to find the median because they are the same.

This applies only for consecutive integers sets not for sets which contain multiples. Test the nos to prove & grasp

Strategy- DS

Remember, on data sufficiency GMAT questions, a definite "no" answer is sufficient, just as a definite "yes" answer is sufficient. A statement will be insufficient only when the answer is "maybe" or "it cannot be determined."

REVISION QUESTIONS

Q6, Quant, MGMAT CAT 4, Marble ratios

Q10, Quant, MGMAT CAT 4, Reverse Primes

Inequalities

While dealing with inequality questions:

1) If there is too much of a hastle testing values: Try to figure out the conceptual approach. Might help.

2) Generally, it is not a good idea to divide an equation or inequality by a variable since dividing by zero is illegal, and a variable might be equal to zero.