A backpack will hold 2,808 grams. If a T-shirt weighs 156,000 milligrams, how many T-shirts will the backpack hold?

18 T-shirts

Step-by-step explanation:

1gram = 1000milligrams

1gram × 156000milligrams ÷ 1000milligrams

The milligrams unit cancel out each other thus grams remains as the main unit.

=156grams

1 T-shirt = 156grams

1 T-shirt × 2808grams ÷156grams

The grams unit cancel out each other thus T-shirt remains as the main unit.

=18 T-shirts

i assume that by 5 you mean 5 gallons.

(20)(0.25) = 15

removing 15 gallons reduces the tank from 20 to 5.