The mass of a wooden crate is 40 kg. Ms. Bowman puts x cantaloupes into the crate. Each cantaloupe has a mass of 0.8 kg. If the total mass of the crate of cantaloupes is 68 kg, how many cantaloupes are put into the crate?
The mass of the wooden crate alone is 40 kg.
The total mass of the cantaloupes is 68 kg.
The total mass of the cantaloupes is subtraction the crate's mass from total mass of the crate and cantaloupes
68 - 40 = <<68-40=28>>28 kg
Each cantaloupe has a mass of 0.8 kg.
28 / 0.8 = <<28/0.8=35>>35 cantaloupes.
Ms. Bowman puts 35 cantaloupes into the crate. Answer: \boxed{35}.