Answer:
Explanation:
Let y represent the distance travelled downwind by the bird from its nest.
Time = distance/speed
A bird leaves its nest and travels 18 miles per hour downwind for x hours. Time spent in travelling downwind is
x = y/18
One the return trip, the bird travels 3 miles per hour slower and has 5 miles left after x hours. It means that the speed at which the bird travelled is 18 - 3 = 15 mph. Also, the distance covered in x hours is (y - 5) miles. Therefore,
x = (y - 5)/15
Since the time is the same, then
y/18 = (y - 5)/15
Cross multiplying, it becomes
15y = 18(y - 5)
15y = 18y - 90
18y - 15y = 90
3y = 90
y = 90/3
y = 30
a) The distance of the entire trip is
30 + 30 = 60 miles
b) time taken for the trip from the nest is
x = y/18 = 30/18
Time taken to return is
x = (y - 5)/15 = (30 - 5)/15 = 25/15
Time for the entire trip is
30/18 + 25/15 = 900/270
= 3 90/270 = 3 1/3 hours
= 3 hours + 1/3 × 60 minutes
= 3 hours 20 minutes
The total trip took 3 hours, 20 minutes and 0 seconds.