A test, a, B, C average score of 91 points, B, C, D average of 89 points, a, D average of 95 points. A, d each score A, B, C three groups of students to plant trees, a, B two groups average of 18 trees per group, a, C two groups average of 17 trees per group, B, C two groups average of 19 trees per group

A test, a, B, C average score of 91 points, B, C, D average of 89 points, a, D average of 95 points. A, d each score A, B, C three groups of students to plant trees, a, B two groups average of 18 trees per group, a, C two groups average of 17 trees per group, B, C two groups average of 19 trees per group

91 × 3-89 × 3 = 6 points
The sum of a and D is 95 × 2 = 190
So a (190 + 6) △ 2 = 98 points
D 190-98 = 92 points

The rectangle of 5cm in length and 3cm in width is rotated around the length and width respectively to get two different geometries, which one has the largest volume

One is 5cm long, 3cm wide and 5cm high, the other is 5cm long, 3cm wide and 3cm high

Who will answer me? Give me a hundred points
There are 44 students in each class. Now we organize the fourth grade students to visit the nursing home. Each class stands in four columns. The front and back two people are 1 meter apart, and the distance between classes is 5 meters. The team travels 30 meters per minute. How many minutes does it take to cross an 80 meter bridge?

How long is each class
(44 △ 4-1) × 1 = 10 (m)
What is the interval between classes
4-1 = 3
What is the length of the team
10 × 4 + 3 × 5 = 55 (m)
It's a long way to go through an 80 meter bridge
(55 + 80) △ 30 = 4.5 (points)