Flight A usually takes 1 hour more than Flight B to travel a distance of 7200 km. Due to engine trouble speed of flight B falls by a factor of 1/6th, so it takes 36 minutes more than Flight A to complete the same journey? What is the speed of Flight A (in km/hr)?
A) 800 B) 900 C) 750 D) 720
Answers
Given: Flight A usually takes 1 hour more than Flight B to travel a distance of 7200 km. Due to engine trouble speed of flight B falls by a factor of 1/6th, so it takes 36 minutes more than Flight A to complete the same journey.
To find: What is the speed of Flight A (in km/hr)?
Solution:
- Now we have given that flight A usually takes 1 hour more than Flight B to travel a distance of 7200 km. So let x be the speed of Flight A be and y be the speed of Flight B .
- Then the equation becomes:
7200/x = 7200/y + 1 .................(i)
- According to the question, we have second equation:
7200/x = (7200 × 6)/5y - 36/60 .................(ii)
- Now equation (i) and (ii), we get:
7200/y + 1 = (7200 × 6)/5y - 36/60
8640/y - 7200/y = 1.6
1440/y = 1.6
y = 900 km/hr
- Putting the value of y in (i), we get:
x = 800 km/hr
Answer:
So the Speed of flight A is 800 km/hr.
Step-by-step explanation:
Given Flight A usually takes 1 hour more than Flight B to travel a distance of 7200 km. Due to engine trouble speed of flight B falls by a factor of 1/6th, so it takes 36 minutes more than Flight A to complete the same journey? What is the speed of Flight A (in km/hr)?
- Let the speed of B be m km / hr
- So per hour B will take 7200 / m hr
- So A takes (7200 / m) + 1 hr
- Therefore new speed of B will be 5m/6 km / hr (decreased by 1/6 or 1 – 1/6 = 5/6)
- Also new time of B will be 7200 x 6 / 5m
- So 43,200 / 5m = 7200 / m + 1 + 0.6 (36 / 60 = 0.6)
- Or 7200 / 5m = 1.6
- Or 8m = 7200
- Or m = 7200 / 8
- Or m = 900
- Now A will take 7200 / 900 + 1
- = 8 + 1
- = 9 hrs
- Therefore speed of A will be 7200 / 9
- = 800 km/hr
Reference link will be
https://brainly.in/question/3702470