The problem is called self-answering problems because the answers are embedded in the question. For example, how many ways can you arrange the letters in the word “six”? The answer is six. At time t=0, water begins pouring into an empty sink so that the volume of water is changing at a rate V′(t)=cost. For time t=k, where \(0≤k≤π/2\), determine the amount of water in the sink.