A student must learn M unfamiliar words for an upcoming test. The rate at which the student learns is proportional to the number of items remaining to be learned, with constant of proportionality equal to k. Initially, the student knows none of the words. Let y(t) stand for the number of the words that the student knows at time t. (a) Wr te down the right hand side of the differential equation satisfied or 5/. (Your answer should be given in terms of y.) gr: dt (b) What is the initial value of 1!? (Give an exact answer.) rm = :1 {c} Suppose that there are 90 words to be learned and that k = 0.5 per hour for this student. Recall that the solution to y' = km - y) with y(D] = D is given by y(t) = Mt]. e'\"). (Give your answers correct to at least three decimal places.) How many hours would it take the student to learn the rst 22 percent of the words? hours How long would it take to learn the next 22 percent of the words? hours How long would it take to learn the next 22 percent of the words? hours (d) The student has Just nished learning the rst 22 percent of the words. (Give your answers correct to at least three decimal pieces.) How long would it take to learn 22 percent of the remaining words? hours After doing this, how long would it take to learn 22 percent of the words that then remain? hours