The Five Most Common GMAT Math Questions

1. Integers and Number Properties If 511 × 45 = 5 × 10k, what is the value of k?

2. Functions For all numbers y such that y ≠ 1, if f(y) = , then

3. Work Problems Four machines, each working at the same constant rate, together can complete a certain job in 12 days. How many machines, each working at the same constant rate, will be needed to complete the job in eight days?

4. Counting Methods Two members of a team are to be selected to represent the team at a national conference. If there are 45 different possible selections of the 2 members, how many members does the team have?

5. Variations of Triangles In the figure shown, if the measure of angle ADB is 20°, the measure of CAD is how many degrees less than the measure of CBD?