Answer :
upstream her speed of 2.4 is decreased by 0.6 to 1.8mph. 2.7mph/1.8m = 1.5 hours
downstream her speed is incresed to 3 mph. 2.7/3 = 0.9 hours
downstream her speed is incresed to 3 mph. 2.7/3 = 0.9 hours