Example: What is the coefficient of 2y?
Answer: 2
Note: Numerical coefficient is the numeral part in a term.

Example: Lucy had 1 blue, 3 green and 4 red pens. What type of a ratio is 3:4??

PQ ∥ RS

FALSE

TRUE

Example: Find the median of the following: 1, 2, 1, 5, 5
Step 1: Sort the list → 1, 1, 2, 5, 5
Step 2: Count of numbers listed → 5 (odd)
Step 3: So the middle number is (count+1)/2 → (5+1)/2 → 3^rd number. Therefore, the median is 2.

Example:

Example: Find the range of the following: 1, 2, 4, 5, 5
Step 1: Sort the list → 1, 2, 4, 5, 5
Step 2: Highest number → 5; Lowest number → 1
Step 3: Difference between the highest and the lowest numbers in the list → 5 - 1 = 4. Therefore, the range is 4.

Example: Find the mode of the following: 1, 2, 4, 5, 5
Step 1: Sort the list → 1, 2, 4, 5, 5
Step 2: Find the number that is repeated the most number of times.
Step 3: In the above list, 5 is repeated twice and all the other numbers occur only once. Therefore, the mode is 5.