An enzyme-catalyzed reaction was carried out with the substrate concentration initially a thousand times greater than the km for that substrate. after 9 minutes, 1% of the substrate had been converted to product, and the amount of product formed in the reaction mixture was 12 μmol. if, in a separate experiment, one-third as much enzyme and twice as much substrate had been combined, how long would it take for the same amount (12 μmol) of product to be formed?