Jyoti can row a boat at $7\frac{1}{2}$ km/h in still water. If in a river running at 1.5 km/h, she takes 50 minutes to row to a place A and come back, then how far off is the place A?

3 km

Jyoti's Speed in still water = 7 1/2 km/h

River's speed 1.5 km/hr

Assume she goes to Distance "D" in upstream and downstream each

Upstream Velocity = 7.5-1.5 = 6 km/hr

Downstream velocity = 7.5+1.5 = 9 km/hr

Time taken to row Upstream, T1 = D/(6)

Time taken to row Downstream, T2 = D/(9)

T1 + T2 = 5/6

D/6 + D/9 = 5/6

(3D+2D)/18 = 5/6

5D = 15

The correct answer is Option (1) → 3 km