On the morning of New Year's Day, 2/9 of the students in the class took part in the singing competition, and 1 of the students in the class played table tennis, which showed that there were students in both activities.
2/9+ 1/4 = 17/36, and the rest.
1- 17/36= 19/36
The number of people who want to go to the movies should be: class size * 19/36. Only when the class number is a multiple of 36, the result can be an integer, and the multiple of 36 within 50 is only 36, so there are 36 students in the class, then
36 * 19/36 = 19 people.
There are 19 people watching movies.
A rope is 62.8 meters long. Is the square it encloses bigger or the circle it encloses bigger?
The side length of a square is
62.8/4 =15.7m.
The area of a square is
15.7 * 15.7 = 246.49 m2
The radius of this circle is
62.8/3.14/2 =10m
The area of a circle is
10 *10 * 3.14 = 314 square meter.
So the area of the circle is very large.