A person x started at 3 hours earlier at 40km/h from a place p, then another person y followed him at 60km/h. Started his journey at 3 o'clock, afternoon. What is the diference in time when x was30 km ahead of y and when y was 30 km ahead of x?
Answers
Answer:
3 hrs
Step-by-step explanation:
Distance = 40km/h
Time = -3hrs
Distance of y = 60km/h
Time of y = 3pm
Time as to when X was 30 km ahead of Y
= (120-30)/20
=4.5h
Time as to when Y was 30 km ahead of X
= (120+30)/20
= 7.5 h
Thus, the required difference in time = 7.5-4.5 = 3
Therefore, the diference in time when x was30 km ahead of y and when y was 30 km ahead of x will be 3 hrs
Answer:
3 hrs
Step-by-step explanation:
Person x started at 12 noon ( 3 hr before 3o clock afternoon)
Speed of person x = 40 km/hr
Distance covered in 3hrs = 40 * 3 = 120 km
person x was 120 km ahead of y when y started
Speed of y = 60 km/hr
Difference in speed of y & x = 60 -40 = 20 km/hr
y covered up 20 km distance every hour
x to be ahead just 30 km of y
y has to cover up 120 - 30 = 90 km
90 km will be covered up by y in = 90/20 = 4.5 hrs
y to be ahead 30 km of x
y need to cover up = 120 + 30 = 150 km
time required to cover up 150 km = 150/20 = 7.5 hrs
the difference in time when x was 30 km ahead of y and when y was 30 km ahead of x = 7.5 - 4.5 = 3 hrs