Question: A student scores 80, 90, and 70 in three subjects. What score does he need in the fourth subject to achieve an average of 85?
Options:
Correct Answer: 95
Solution:
Total score needed for average of 85 = 4 * 85 = 340. Current total = 80 + 90 + 70 = 240. Score needed = 340 - 240 = 100.