If a cook prepares a meal in 6 hours and a second cook prepares it in 7 together with a third cook they prepare it in 2 hours. how long does it take the third cook to prepare the meal alone

One astronomical unit (1 au) is about 1.496 alt tag missing. kilometers. if you wrote this number of kilometers in regular decimal notation (for example, 528 and 3,459 are written in regular decimal notation), how many zeros would your number have?