X leaves his house facing west, drives 100 km, then turns right and drives 100 km. He then turns left and drives 50 km. In which direction is X facing in relation to his starting point?
A can complete a task alone in 8 days, while B takes 12 days to do it by herself. Together with C it takes them 4 days to complete the work. If C and D together can complete the task in 15 days, then how many days will D need to complete the task by herself?