## Thursday, April 14, 2011

### 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}

## Monday, April 11, 2011

### 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.
A quantity that is cubed retains its original sign: if it starts out positive, it remains positive and if it starts out negative, it remains negative.

### Brahamastra

Keep Cool. Read Properly. KKEEP IT COOL

## Wednesday, April 6, 2011

### Decimals

tenths digit is the first digit to the right of the decimal point.

### Similar Triangles

Triangles are defined as similar if all their corresponding angles are equal or if the lengths of their corresponding sides have the same ratios.

First, recall that in a right triangle, the two shorter sides intersect at the right angle.

if two similar figures have lengths in a given ratio (say A:B), then their areas will have a ratio that is the square of this length ratio (i.e.,A2:B2). Conversely, if the areas are in a given ratio, then the lengths will be in the square root of that ratio. ( Look at MGMAT CAT 4. q 19) Excellent example.