A student scores 60, 70 and 80 in three tests. What must be scored in a fourth test to average 75?
- A. 85
- B. 90
- C. 95
- D. 80
Explanation
An average of 75 over four tests needs a total of 300, and the first three sum to 210, so the fourth must be 90. Working from the required total rather than adjusting the average directly is the safer method. The answer exceeds 75 because the earlier scores pulled the average down.
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