Then tomorrow do 11 pushups then the following day do 12 then 13, 14, 15, 16 and so on. Do only a single set of pushups everyday, increasing the amount by just 1 pushup daily.
No more, no less, until you reach 100 pushups. It can be done everyday or every other day, but it has to be consistent. This slow but predictable and gradual progress to the body makes it possible for almost anyone to reach the coveted 100 pushups mark.