x & lt 17:

Substitute y into the inequality, multiply both sides by 9, and work out.

Maximum total score:

The average score of five games is less than 17 (note, not including equal to. Because the average score can be a fraction, it is not easy to determine the maximum value. ), so the total score of five games is less than 5× 17. "Total score" is an integer, and the maximum is 5× 17- 1.

(3)

Minimum total score:

If the average score exceeds 18, the total score should exceed 18× 10 (please note that "exceeding" does not include equal to, and the total score is still an integer. )。 So the minimum value is 18× 10+ 1 min.

PS: When the given value must be an integer, ">" and "