To complete the order olivia need to work 145 minutes.
Step-by-step explanation:
      The given is,
          Olivia can make 2 stone crafts in 45 minutes.
          She has been working for 35 minutes on an order for 8 stone crafts.
Step:1
      To find the Time to make 1 stone craft
      Time for 1 stone craft = 45÷2
                         = 22.5 minutes
Step:2
      Total time to complete the order
                      = No. Of stone crafts × Time for 1 stone craft
                      = 8 × 22.5
                      = 180 minutes
Step:3
    Time to complete on an current order,
         Remaining time to work = Total time - Already worked time
                              = 180 - 35
                              = 145 minutes.
Results:
     Olivia need to work 145 minutes to complete on an order for 8 stone crafts.
