To find the original quantity when given the percent it was reduced and the amount left, divide the amount left by the percentage that is left:
The bottle was reduced by 85%, which means there is 15% left left in the bottle ( 100% - 85% = 15%)
Now divide the amount left by the percentage left:
20 / 0.15 = 133.33
The original amount was 133.33 milliliters ( Round answer as needed)
