In the sixth grade, 50 students took part in the math competition, with an average score of 63, including 60 for boys and 70 for girls. How many more boys than girls?

All the above equations are used. I wonder if you can understand them. Let me use arithmetic! Which one you can adopt is easy to understand!

Assuming that the contestants are all boys, the average score is 60;

If there are/kloc-0 girls, the total score is 70-60 = 1 0, and the average score is10 ÷ 50 = 0.2;

If there are two girls, the total score is 10× 2 = 20, and the average score is 20 ÷ 50 = 0.4;

…………

In fact, the average score is 63, 3 points more than 60, so the number of girls participating in the competition is: 3 ÷ 0.2 =15;

Number of boys: 50-15 = 35;

There are more boys than girls: 35- 15 = 20.

Test: The total score of boys is 60× 35 = 2 100, and that of girls is 70× 15 = 1050. The average score is:

(2 100+ 1050)÷50=63

Please accept it if you feel clear!