You need the starting point, and another point that helps direct where the ray is aimed. Call these two points A and B.
Saying "Ray AB" means we extend a line through AB such that the line goes forever through B and beyond B, but we do not do the same for point A. The point A is effectively a cliff where no road goes on the other side of it. Check out the diagram below to see what I mean. The arrow means the line goes on forever in that direction.
Answer:
The number of cases prior to the increase is 50.
Step-by-step explanation:
It is given that the number of measles cases increased by 13.6% and the number of cases after increase is 57.
We need to find the number of cases prior to the increase.
Let x be the number of cases prior to the increase.
x + 13.6% of x = 57
Divide both the sides by 1.136.
Therefore the number of cases prior to the increase is 50.