Sheena can row a boat at 2.60 mi/h in still water. She needs to cross a river that is 1.20 mi wide with a current flowing at 1.80 mi/h. Not having her calculator ready, she guesses that to go straight across, she should head upstream at an angle of 25.0° from the direction straight across the river.
What is her speed with respect to the starting point on the bank?