Rahul takes 133 ⅓% more time to cover a distance in upstream as compare to cover same distance in downstream

Rahul takes 133 ⅓% more time to cover a distance in upstream as compare to cover same distance in downstream. If his friend’s speed and his speed are in ratio 6 : 7, when they go in downstream, then find the ratio of speed of Rahul and his friend in still water. (Speed of stream is same in both cases)

(a) 4 : 5

(b) 5 : 4

(c) 7 : 6

(d) 3 : 5

Sol:

Let times by Rahul to cover a distance ‘D’ in downstream is → 3x

So, time taken to cover ‘D’ distance in upstream → 7x

⇒ Speed of Rahul in downstream and upstream be 7x and 3x respectively