Answer:
30 mi/ 24 mi (6 mi slower)
Step-by-step explanation:
distance = rate x time
distance = 20 mph * X hr = 20 X miles
return trip:
distance = 16 mph * X hr + 6 miles = 16X + 6
They are the same:
20X = 16X + 6
4X = 6
X = 6/4 = 3/2
20 mph * 3/2 hr = 30 miles.
On the return trip: 16 mph * 3/2 hr = 24 miles, which is 6 miles short of 30 mi.
The distance is 30 miles.
The bird flies all 30 miles in 3/2 hr = 1 and 1/2 hour = 1 hour 30 minutes.
On the return trip, the bird flies 24 miles in 1.5 hours, which is 6 miles short.