A jet flew from Tokyo to Bangkok, a distance of 200 km. On the return trip, the speed was decreased by 50 kmph. If the difference in the time of the flights was 2 hours. How much time will it take from Tokyo to Bangkok? - Sri Chaitanya Infinity Learn Best Online Courses for NCERT Solutions, CBSE, ICSE, JEE, NEET, Olympiad and Class 6 to 12

A
1 hour
B
2 hours
C
3 hours
D
4 hours

Solution:

distance = 200 km
When the jet flew from Tokyo to Bangkok . let time taken be ‘t1’ with ‘x’ kmph
𝐷𝑖𝑠𝑡𝑎𝑛𝑐𝑒
t= = t1
𝑠𝑝𝑒𝑒𝑑

= 200
𝑥

-------(i)
When jet flew Bangkok to Tokyo let time be t2 with speed x-50 kmph
t = 200
𝑥−50
= t1-t2 = 2
1 1
= 200(
𝑥
= 100(1
𝑥

- ) = 2
𝑥−50
- 1 ) = 1
𝑥−50
𝑥−50−𝑥
= 100 ( ) = 1
(𝑥−50)
= x2 - 50+ 5000= 0
= x2 - 100x + 50 x + 5000=0
= x (x-100)+ 50 (x+100) = 0
= (x-100) (x+50) x= 100 04 x=-50
x=100 kmph
T = 200
𝑥

= 2 hours

Solution:

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