Three resource types (RES 1, RES 2, and RES 3) are to be assigned to a certain task. RES 1 working alone can complete the task in 35 days, RES 2 working alone can complete the task in 40 days, and RES 3 working alone can complete the task in 60 days. Suppose 1 unit of RES 1 and 1 unit of RES 2 start working on the task together at time 0 . Two units of RES 3 are brought in to join the task sometime after time 0 . RES 2 quits the task when there is \(20 \%\) of the task remaining. If the full task is desired to be completed 13 days from time 0 , determine how many days from time 0 the 2 units of RES 3 should be brought in to join the task. Assume that work rates are constant and units of the same resource type have equal work rates.