A Police Officer walks from his house at 4 km
per hour and reaches his office 5 minutes late.
If his speed is 5 km per hour, he will reach his
office 10 minutes early. How far is his office
from the house?
Answers
Answer:
5 km
Step-by-step explanation:
Distance = Speed*Time
Change speed to km per minute by dividing by 60.
Let t be the time it would take if he arrived exactly on time.
Set up two equations for distance using the two given situations.
d = (4/60)(t+5) = (t+5)/15
d = (5/60)(t-10)= (t-10)/12
Set equations equal and solve for t:
15(t-10) = 12(t+5)
15t - 150 = 12t + 60
3t = 210
t = 70
Finally, substitute t back into one of the equations for d:
d = (70+5)/15 = 75/15 = 5
The office is 5 km from his house.
**Additional Note:
Given this distance, you can also find the ideal speed to walk to arrive at the office in exactly 70 minutes.
Let v be ideal speed.
d = v*t
v = d/t = 5/70 = 1/14
Multiply by 60 to convert back to km per hour.
v = 60/14 ~ 4.3 km/hr
Answer:5 km
Step-by-step explanation:
Let the distance be x km.
And time taken to cover this distance be a.
A.T.Q
4*(a+5)=5*(a-10)
4a+20=5a-50
5a-4a=20+50
a=70 minutes.
Distance=Time*Speed
x=(70-10{1 hour or 60 min.})*5
x=5 km
Plz mark me as the brainliast........