a little late, but to find out the output for 24.5, you first need to find the "rule" for this table. in other words, you need to figure out what equation they're using to get these outputs
they're doing SOMETHING to the x values to get the y values. take your outputs, y, and divide them by your inputs. see if you run into a pattern.
14/4 = 3.5 17.5/5 = 3.5 21/6 = 3.5 24.5/7 = 3.5
... and you do. the equation here is probably y = 3.5x, because every x value appears to be multiplied by 3.5 to get the y value.
so, you can find the output for 24.5 by multiplying it by 3.5 24.5 * 3.5 = 85.75
for some reason, it seems like they rounded down to 84? not quite sure why. 84/24.5 is about 3.4, which isn't as precise, but it's the closest to the result. i would choose A.
