Step-by-step explanation: Well there are 5 cats and each cat drinks .15 liters per day. .15x5 = .75 liters of water. 1.55 liters - .75 liters = 0.8 liters left.
It is hard to explain in my opinion but I can try. For the stem column you, basically factor out the first digit of the number. Then the leaf column you, put the second digit of each number in your data set.