A journey of 800 km is done in a total of 10 hours . If 320 km is travel by train and remaining by bus . The same journey is done in 8 hours if 240 km is travel by train and remaining is done by bus . Find the ratio of the speed of the speed of train to bus .

Options

A. `2:11`
B. `3:11`
C. `1:11`
D. `4:11`

Answer

C

Explanation

`{:("Case"1 : , 320 T + 480 B , to , 10 "hours") , ("Case" 2 : , 240 T + 560 B , to , 8 "hours"):}`
In case 1 , 80 km journey extra is done by train , which increases time by 2 hours .
If remaining journey of 480 is also done by train only then time will increase by `6 xx 2` hours = 12 hour
`therefore` Train will take (10 + 12) hours to complete 800 km
Similarly , in case 2 , 80 km journey extra is done by bus , which decreases time by 2 hours .
If previously 240 kms were also covered by bus , then time would be reduced by `( 2 xx 3)` hours = 6 hours
`therefore` Bus will take (8-6) hours to complete 800 km
`therefore` Ratio of speed = `((800)/(22))/((800)/(2)) = 1 : 11`