GIVEN: (i) Boat’s speed in still water = 12 kmph
(ii) Stream’s speed = 5 kmph
(iii) Total Distance covered by boat in upstream and downstream = 96km
CONCEPT: (i) Distance and speed are in direct proportion to each other.
FORMULA USED: (i) Upstream speed = Speed in still water – Stream’s speed
(ii) Downstream speed = Speed in still water + Stream’s speed
(iii) Speed = Distance travelled/Time taken
CALCULATIONS: Speed of boat downstream = 12 + 5 = 17 km/hr
Speed of boat upstream = 12 – 5 = 7 km/hr
As he travelled total (T) hours
⇒ Total distance covered = 119 km
⇒ (
) + (
) = T
⇒ T = 24 hours
∴ Value of T = 24 hours.