If the cooking time is 4.33 hours and the food should be ready by 17:15pm what time should we start cooking

for this purpose we will separate the hours from given time

the time at which cooking started = 17:15 - 4.33

= 12.82 pm is the answer ...

in other way 17 : 15 is 5:15 when we subtract 4. 33 from it it will be 0: 82 means 12:82 pm ...

17: 15 is 5:15 so 5:15 minus the cooking time 4.33 = 1:18, so you start cooking at 1:18.