Working independently, susan can perform a certain task in 6 hours and tom can perform it in 7 hours. if susan and tom work together at the task for 3 hours, at which point susan leaves, how many hours will it take tom to complete the task alone?

0.5 hr = 30 minutes

Explanation:

Let the total amount of work to be done = 42 units

Thus, efficiency of Susan = 42 units / 6 hours = 7 units/hr

Efficiency of Tom = 42 units / 7 hours = 6 units/hr

They worked together for 3 hours, which means that total efficiency = 7 + 6 units/hr = 13 units/hr

Thus, Amount of work done = 13 units/hr * 3 hr  = 39 units

Amount of work left which must be completed by Tom alone = 42 - 39 units = 3 units

Thus, Time taken by Tom:

Thus, Time taken by tom = 0.5 hr = 30 minutes

the economic difference between the three colonial regions. shipbuilding, whaling, fishing, and trapping where also main factors to the economy. the southern regional colonies economy was based on sugarcane, rice, cotton, tobacco, and indigo.

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