A senior citizen walks 275 m in 25 min going around a shopping mall. If she wants to increase her average speed by 25 % in walking a second lap, what would her travel time in minutes have to be?
Distance = speed * time
= (1.25*speed)*((1/1.25)*time)
= 25 min./1.25
= 20 minutes
45
To solve this problem, we need to first find the senior citizen's current average speed. We can do this by dividing the total distance she walks by the time it takes her.
The formula to calculate average speed is:
Average Speed = Distance / Time
Given that the senior citizen walks 275 m in 25 min, we can substitute these values into the formula:
Average Speed = 275 m / 25 min
Now, let's calculate the current average speed:
Average Speed = 11 m/min
To increase her average speed by 25%, we need to find 25% of her current average speed and add it to the original average speed.
25% of 11 m/min = (25/100) * 11 m/min = 2.75 m/min
So, we need to increase her average speed by 2.75 m/min.
To calculate her new average speed, we need to add this increase to her current average speed:
New Average Speed = 11 m/min + 2.75 m/min
New Average Speed = 13.75 m/min
Now that we have the new average speed, we can calculate the time it takes her to walk a second lap using the formula:
Time = Distance / Average Speed
We know the distance is the same as the first lap, which is 275 m. Substituting the values into the formula:
Time = 275 m / 13.75 m/min
Calculating the travel time:
Time = 20 min
Therefore, her travel time for a second lap, if she wants to increase her average speed by 25%, would be 20 minutes.