Question
The ratio of the speed of boats ‘A’ and ‘B’ in
still water is 8:9, respectively. The speed of the current is 25% of the speed of boat ‘A’ in still water. If boat ‘A’ takes 10 hours to travel 500 km downstream, then find the time taken by boat ‘B’ to travel 70 km upstream and 275 km downstream. (Note: Both the boats are rowing in the same stream.)Solution
Let the speeds of boats ‘A’ and ‘B’ in still water be 8x km/hr and 9x km/hr Therefore, speed of the current = 0.25 × 8x = 2x km/hr According to the question, 8x + 2x = 500/10 Or, 10x = 50 Or, x = 5 Therefore, upstream speed of boat ‘B’ = 9x – 2x = 7x = 35 km/hr Downstream speed of boat ‘B’ = 9x + 2x = 11x = 55 km/hr Required time taken = (70/35) + (275/55) = 2 + 5 = 7 hours
- Anita takes 3 hours to travel from city 'A' to city 'B' at the speed of 60 km/h. After that, she increases her speed by 40% and takes 2 hours to travel fro...
A boy goes to school with a speed of 75 km/h and comes back with a speed of 45 km/h. find his average speed?
Compare the rates of two trains, one travelling at 40 km an hour and the other at 30 m a second?
Ravi appointed 24 workers to finish a job in 18 days. After 9 days, he saw that only 1/3 of the job was completed. If 'n' is the number of additional wo...
- The ratio of the speeds of Priya and Diya is 6:5 respectively. Sneha can cover 720 km in 12 hours. If the speed of Diya is 20% less than that of Sneha, how...
- Bus 'X' and Bus 'Y' start together from a station heading in the same direction. Bus 'X' moves at 18 km/h while Bus 'Y' moves at 30 km/h. Determine the dis...
- Rohit jogs at a pace of 14 km/h and takes 11 hours for his fitness trail. What speed does he need to jog at to finish it in just 7 hours?
X started to run from point ‘A’ to ‘B’ at a speed of 30 km/hr at 9:00 am and Y started to run from point ‘B’ to ‘A’ at a speed of 14 km/...
A car moving at a speed of 54 km/hr covers a certain distance in ‘x’ hours. If the same distance is covered at a speed of 72 km/hr in (x - 1.5) hour...
A thief and a policeman are 80 km apart. The thief is traveling at a speed of 48 km/h, while the policeman is moving at 80 km/h. How far will the police...
