To find the total bill, let's assume the total bill to be the unknown x. Knowing that Abby paid 20% of the total bill, which amounted to $14.25, we can write an equation to describe this scenario as:
20% * x = 14.25
0.2 * x = 14.25 (converted 20% to it's decimal form by dividing 20 by 100 which is 0.2)
Now we can solve for x by dividing both sides by 0.2, which gives:
x = 14.25/0.2
x= 71.25
Thus, the total bill was $71.25
Hope this helps!