DRDO Multi tasking staff Model paper 5

Let speed of boat in still water is SB and speed of current is SC and Speed of boat in upstream and downstream is SU and SD .
Speed of boat in still water SB = 18 km/hr
Speed of current, SC = 2 km/hr
Speed of boat in upstream, SU = 18 - 2 = 16 km/hr
Speed of boat in downstream, SD = 18 + 2 = 20 km/hr
∴ Total distance travelled = 3 × 16 + 2 × 20 = 48 + 40 = 88 km