Five half-full classes + three 3/4 full classes + 2 1/8 empty (which is 7/8 full) classes altogether give us 10 classes without 70 students. Let's assume that one class is x, so we can write it as:
5 * 1/2x + 3 * 3/4x + 2 * 7/8x = 10x - 70
After multiplying and changing it to decimals:
2,5x + 2,25x + 1,75x = 10x - 70
6,5x = 10x - 70 / - 6,5x (both sides)
0 = 3,5x - 70 / + 70 (both sides)
70 = 3,5x / :3,5 (both sides)
x = 20
Check:
5 * 1/2 * 20 + 3 * 3/4 * 20 + 2 * 7/8 * 20 = 10 * 20 - 70
5 * 10 + 3 * 15 + 2 * 17,5 = 200 - 70
50 + 45 + 35 = 130
130 = 130
Correct - there are 20 students in each class (200 students overall)
Answer: There are 200 students in the school when no students are absent.
We know how we got 90, since a right angle is 90 degrees,
180 degrees are in a triangle.
180-90=90
Find the pair that equals 90 so you get 180 degrees!
If you have more questions don’t have hesitation to ask!
Or add all number to get 180 degrees!
The hand went around 7 numbers.
