
Answer: Given : Â A plane flies from Penthaven to Jackson and then back to Penthaven. When there is no wind, the round trip takes 6 hr 24 mins , but when wind is at 50 miles per hr than 6 hrs 40 mins.
To find : distance from Penthaven to Jackson
Solution:
Let say Plane speed when no Wind  =  P  Miles/hr
& Distance between Penthaven to Jackson = D Miles
Time taken in round trip  =  D/P  + D/P
= 2D/P Â
6 hr 24 mins  = 6 hr + 24/60  hr  = 6.4 hrs
=> 2D/P Â = 6.4
=> D/P = 3.2 Â
=> P = D/3.2
when there is a wind blowing from Penthaven to Jackson at $50$ miles per hour,
=>  Time taken  =  D/(P + 50)  + D/(P - 50) Â
Time taken =  6 hr 40 mins = 6 hr + 40/60 hr  = 6  + 2/3  = 20/3  hrs
=> D/(P + 50) Â + D/(P - 50) Â Â = 20/3
=> 3D(P - 50+ P + 50)  = 20(P² - 2500)
=> 3D ( 2P ) = 20(P² - 2500)
=> 3D P  = 10 (P² - 2500)
=> 3D (D/3.2)  = 10 ( (D/3.2)² - 2500)
=> 3D²  * 3.2  = 10 ( D²  - 25600)
=> 9.6D²  = 10D² -  256000
=> 0.4D² = 256000
=> D² = 6,40,000
=> D = 800
distance from Penthaven to Jackson  = 800 Miles
Additional info :
Plane speed = 800/3.2 Â = 250 miles per hr
Step-by-step explanation:
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