Inequality questions

[vsrc100]

All,

 

I'm worried ab't the above type of questions in the GMAT.

I'm missing these in the practice tests.Can you provide me

with some tips to crack these.

 

TIA.

[ursula]

Most people have more trouble with inequalities than with straight equalities. Here are some rules to keep in mind when manipulating inequalities:

 

1) You can add or subtract the same quantity from each side:

For example, if a

 

2) You can multiply or divide an inequality BY A POSITIVE QUANTITY:

For example, if a

 

3) You can multiply or divide an inequality by a NEGATIVE QUANTITY, but you MUST FLIP the orientation of the inequality:

For example, if a [/color] -5b and -a/5 > -b/5

 

4) You can ADD two inequalities that have the SAME orientation:

For example, if a

Similarly, if a > b and c > d then a+c > b+d

 

This last rule is similar to what you would use when solving two simultaneous linear equations by adding them together. However, be careful! With inequalities you can only ADD them, not subtract them, so:

If a

For example, 6

This allows you to conclude that 6+2

but it DOES NOT MEAN that 6-2

(Subtracting inequalities would be similar to adding them after first multiplying one of them by -1, but that would require flipping its direction, so they would no longer match).

 

Hope this helps...