Subtract 220 with 48, then add 96. Last step would be subtracting 220 with the amount they have now in those 3 days to find how much points the stock market gained in those 3 days.
Subtract 220-48.It‘ll be 172.
Add 172 with 96. 172+96=268.
Subtract 268 with how much points the stock market had 3 days ago. 268-220 would be 48.
The 1:3 ratio means that the distance from A to the point is 1/4 of the distance from A to B.
The difference of y-coordinates is 10-8 = 2. 1/4 of that is 2·1/4 = 1/2, so the point of interest will have y-coordinate 8 + 1/2 = 8 1/2. This apparently corresponds to the first selection: