Problem:
Amar is walking around a rectangular field that measures 72m by 58m. He walks at a rate of 3km per hour. How much time will he take to complete 2 rounds?

Solution:
To find the time Amar will take to complete 2 rounds, we need to calculate the total distance he needs to cover and then divide it by his walking speed.

Step 1: Calculate the total distance:
The total distance Amar needs to cover for 1 round is equal to the perimeter of the rectangular field. The formula for the perimeter of a rectangle is 2(length + width). So, the total distance for 1 round is:

2(72m + 58m) = 2(130m) = 260m

Step 2: Calculate the total time:
Next, we need to calculate the total time Amar will take to cover the total distance of 2 rounds. We can use the formula:

Time = Distance / Speed

The total distance for 2 rounds is 2 * 260m = 520m. And Amar's walking speed is 3km per hour, which is equivalent to 3000m per hour. So, the total time is:

Time = 520m / 3000m/hour

Step 3: Convert the time to hours:
To convert the time to hours, we divide the total time by 60 (as there are 60 minutes in an hour). The remainder will give us the minutes.

Time in hours = 520m / 3000m/hour / 60 = 0.028 hours

Step 4: Convert the time to minutes:
To convert the remaining decimal part of the time to minutes, we multiply it by 60.

Time in minutes = 0.028 hours * 60 = 1.68 minutes

Step 5: Calculate the total time:
Finally, we add the hours and minutes together to get the total time.

Total time = 0 hours 1.68 minutes

Therefore, Amar will take approximately 0 hours and 1.68 minutes to complete 2 rounds around the rectangular field.