Jacob used 1/7 of a liter of water to fill 1/9 of the fish aquarium. How many liters of water are needed to fill the aquarium?

Jacob used 1/7 of a liter of water.

He needs to fill 1/9 of the fish aquarium.

Find how many liters would Jacob need to fill the aquarium

=> Let x = liters of water need to fill the aquarium

=> x/1 = 1/7 divided by 1/9

=> x = 1/7 x 9/1

=> x = 9/7, since this is an improper fraction, let’s convert it to mixed fraction

=> x = 1 and 2/7

So, Jacob need 1 and 2/7 liter of water to fill the whole aquarium.