The mode is the number that appears most often in a set of numbers.

$\displaystyle 89, 88, 88, 100, 75, 88, 78, 91, 92, 82$

If we order our number set we get the following:

$\displaystyle 75, 78, 82, 88, 88, 88, 89, 91, 92, 100$

In this case, because Henry scored 88 three times, that is the mode.

The mode is the number that occurs the most in a group.

Rearranging our numbers we get:

$\displaystyle 2, 2, 2, 3, 4, 6, 6, 7, 8, 10$

While $\displaystyle 6$ does occur twice, $\displaystyle 2$ occurs three times, and no other number does, so $\displaystyle 2$ must be the mode.

The correct answer is 6.

If we reorganize our set in ascending order we get the following:

$\displaystyle 1, 1, 2, 2, 3, 4, 4, 4, 5, 5, 6, 6, 6, 6, 7, 7$

The mode is the number in a set that appears the most often.

In this particular number set, 6 appears four times and no other number appears more than three times. 

The mode of a data set is the number that occurs most often. Because Steven managed to long jump 15 feet 3 times, 15 feet is the mode.

In a data set, the mode is the number that occurs most frequently.

Because 18 of his classmates only had 1 sibling, 1 is the number that appears most often.

The mode in a set of numbers is the one that appears most frequently.

Because $140 appears 3 times, more than any other number, it must be the mode.

The mode is the number that is repeated most often. In this set of scores, the two numbers repeated are 76 (repeated twice) and 86 (repeated three times). Since 86 is repeated most, it is the mode.

The mode is the number that appears the most within a set of numbers. Since no number is repeated in this set, there is no mode.

The mode is the number in a set that appears the most. Since there are two numbers within the set of five test scores that appear twice, choose the number that is above $\displaystyle 80\%$, which is 82. The mode is $\displaystyle 82$.

$\displaystyle \{ 3, 7, 8, 9, 10, 10, 10, 10, 11, 11, 13, N \}$ is the correct set; no matter what $\displaystyle N$ is, no value other than 10 can appear four or more times.

To see that no other choice works, let's examine them.

$\displaystyle \{ 7, 8, 9, 10, 10, 11, 11, 13, N \}$: If $\displaystyle N$ is any number other than 10 or 11, then the number has 10 and 11, and possibly one other number, as modes, each appearing twice.

$\displaystyle \{ 1, 2, 3, 4, 5, 6, 7, 8, 9, N \}$ : If $\displaystyle N$ is not any of the numbers already in the set, the set has no repeated values and thus no mode.

$\displaystyle \{ 8, 8, 8, N, N, N \}$: If $\displaystyle N \neq 8$, then the set is bimodal, with 8 and $\displaystyle N$ the modes.

$\displaystyle \{ 9, 10, 10, 10, 10, 11, 11, 13, N, N \}$ : If $\displaystyle N = 11$, the set is bimodal, with 10 and 11 the modes.