Answer:
B. 4
Step-by-step explanation:
Interval: 19-21
Scores that are between 19 and 21 are underlined:
Scores in order: <u>20, 21, 21, 21</u>, 23, 25, 26, 27, 27, 29
Multiply the first 3 prime numbers that are 2 3 and 5 so the answer would be 30
400 - 3x = 163
Add 3x to both sides.
400 = 163 + 3x
Subtract 163 to both sides.
237 = 3x
237/3 = 79