1. A man's speed with the current is 15 km/hr and the speed of the current is 2.5 km/hr. The man's speed against the current will be 10 km/hr.
2. The speed of a boat in still water is 22 km/hr. and the rate of current flow is 3 km/hr. The distance travelled in downstream direction in 12 minutes will be 5 km.
Select the answer using the code given below:
To determine the correctness of the statements given in the question, let's analyze each one by applying relevant concepts.
- Statement 1: A man's speed with the current is 15 km/hr and the speed of the current is 2.5 km/hr. The man's speed against the current will be 10 km/hr.
- Let's denote: \(S_m\) = Speed of the man in still water (unknown), \(S_c\) = Speed of the current = 2.5 km/hr.
- The man's speed with the current is given by \(S_m + S_c = 15\, \text{km/hr}\).
- Hence, \(S_m = 15 - 2.5 = 12.5\, \text{km/hr}\).
- The man's speed against the current would be \(S_m - S_c = 12.5 - 2.5 = 10\, \text{km/hr}\). Thus, statement 1 is correct.
- Statement 2: The speed of a boat in still water is 22 km/hr, and the rate of current flow is 3 km/hr. The distance travelled in the downstream direction in 12 minutes will be 5 km.
- The speed of the boat in downstream is \(S_b + S_c = 22 + 3 = 25\, \text{km/hr}\).
- Time given is 12 minutes, which is \(\frac{12}{60} = \frac{1}{5}\) hours.
- Distance travelled downstream = Speed × Time = \(25 \times \frac{1}{5} = 5\, \text{km}\). Thus, statement 2 is also correct.
Based on the analysis of both statements, the correct answer is Both 1 and 2.
Important Questions from Partial Speed
A train having length 210 metres takes 25 seconds to cross a 540 metres long bridge. How much time will the train take to cross a 630 metres long bridge?
A person X from a place A and another person Y from a place B set out at the same time to walk towards each other. The places are separated by a distance of 15 km. X walks with a uniform speed of 1.5 km / hr and Y walks with a uniform speed of 1 km / hr in the first hour, with a uniform speed of 1.25 km / hr in the second hour and with a uniform speed of 1.5 km / hr in the third hour and so on.
Which of the following is / are correct?
1. They take 5 hours to meet.
2. They meet midway between A and B.
Select the correct answer using the code given below:
The speed of a train is 120 kmph. What is the distance covered by it in 15 minutes?
I walk a certain distance and ride back taking a total time of 37 minutes. I could walk both ways in 55 minutes. How long would it take me to ride both ways ?
Karan had covered two third of a certain distance when his car had a breakdown. He parked it and covered the remaining distance on foot. His time of travel on foot was 9 times his time of travel on car. What is the ratio of his walking speed with respect to his car’s speed?
