GMAT Shortcuts

Question 1

3^8 - 2^8

Answer 1

Looks similar to x^2-y^2 = (x+y)(x-y). Look for identifying patterns to link harder problems to easier ones

Question 2

X items(price) + Y items(price) = something

Answer 2

Integer constraint. Test out numbers until you reach a conclusion

Question 3

When setting up chart for weighted average what items go on top?

Answer 3

Items that change represent columns while the items that are constant represent rows.

Question 4

Percent change and weighted average

Answer 4

If you aren’t given any actual amounts, but asked for a ratio or percent, you can pick values and plug in; however, you can only pick 1 smart number

Question 5

Percent change and weighted average formulas use the following chart:

Answer 5

Items that change represent columns while the items that are constant represent rows. Columns should be labeled: Old - Change - Total/New.

Question 6

Estimating: When you reduce denominator estimation is…

Answer 6

Overestimated

Question 7

Estimating: When you increase denominator estimation is…

Answer 7

Underestimate

Question 8

Estimating: When you increase numerator estimation is…

Answer 8

Overestimated

Question 9

Estimating: When you Decrease numerator estimation is…

Answer 9

Decreased

Question 10

When working with averages and ratios:

Answer 10

All you need to calculate the average of one of the 2 groups is the ratio and the mean and one of the group’s average

Question 11

When you see multiples of a number, you can…

Answer 11

Factor out a common factor

Question 12

When do you use variables of overlapping sets

Answer 12

Percents of a certain group