please solve it step by step, how do we get this number

A stop-watch time study made in a woodworking shop of a lathe operation produced following results:. Observations (minutes/cycle) job 1 2 3 4 5 Br 1 45 43 40 44 39 422 401 306 2 .30 31 .33 .29 30 -300 3 .80 .83 .80 .81 82 .812 893 Elements 1 and 3 are performed by the operator, element 2 is completely performed by the machine. Performance rating for the element 1 is 90% and for element 3 it is 110%. If the shop allows worker to have 10% of the daily working hour for prayer, 12% of the daily working hour for personal time and 5% of the daily working hour moorning delay. a) Calculate the standard time for the operation. b) Calculate the number of unit produce in three shift of six hours