I got 77 points in math, 87.5 points in Chinese and 90 points in English. Do I have to make up lessons?
Because the average score of Chinese and mathematics is 87.5, the total score of Chinese and mathematics is 87.5× 2 = 175, while the average score of the three subjects outside the number of languages is 89.5, and the total score of the three subjects outside the number of languages is 89.5× 3 = 268.5, so English is 269.5- 175.5 = 94.