Question : A boat can go 40 km downstream and 25 km upstream in 7 hours 30 minutes. It can go 48 km downstream and 36 km upstream in 10 hours. What is the speed (in km/hr) of the boat in still water?

Option 1: 6

Option 2: 12

Option 3: 9

Option 4: 15

Question : A boat goes 2 km upstream and 3 km downstream in 20 minutes. It goes 7 km upstream and 2 km downstream in 53 minutes. What is the speed (in km/hr) of the boat in still water?

Option 1: $\frac{75}{7}$

Option 2: $\frac{120}{7}$

Option 3: $\frac{135}{7}$

Option 4: $\frac{150}{7}$

Question : A boat goes 12 km downstream and comes back to the starting point in 3 hours. If the speed of the current is 3 km/h, then the speed (in km/h) of the boat in still water is:

Option 1: 12

Option 2: 9

Option 3: 8

Option 4: 6

Question : A boat covers 24 km upstream and 36 km downstream in 6 hours, while it covers 36 km upstream and 24 km downstream in $6\frac{1}{2}$ hours. The speed of the current is:

Option 1: 1 km/hr

Option 2: 2 km/hr

Option 3: 1.5 km/hr

Option 4: 2.5 km/hr

Question : A boat travels 60 kilometres downstream and 20 kilometres upstream in 4 hours. The same boat travels 40 kilometres downstream and 40 kilometres upstream in 6 hours. What is the speed (in km/hr) of the stream?

Option 1: 24 km/hr

Option 2: 16 km/hr

Option 3: 18 km/hr

Option 4: 20 km/hr