1. Two places A and B are 80 km apart from each other. Two cars start from A and B Suppose the speed
of car starting from A is greater than the speed of car starting from B. If they move in the same direction
at the same time, they meet in 8 hours and if they move in opposite direction they meet in 1 hour and
20minutes. Find the speed of the cars.
Answers
Step-by-step explanation:
Let the speed of car starting from A=x km/hr and speed of car starting from B=y km/hr.
The relative speed of A with respect to B when moving in the same direction =x−y km/hr.
The relative speed of A with respect to B when moving in opposite direction =x+y km/hr.
Distance between A and B=80 km.
We know, Time=
Speed
Distance
From the above information, we have,
x−y
80
=8and
x+y
80
=1+
60
20
=
3
4
or,
x−y
80
=8
⇒10=x−y
⇒x−y=10....(i)
Also,
x+y
80
=
3
4
⇒240=4(x+y)
⇒x=60−y....(ii)
Substituting (ii) in (i), we get,
x−y=10
⇒60−y−y=10
⇒60−2y=10
⇒2y=50
⇒y=25
Substituting y=25 in equation (ii), we get,
x=60−y
⇒x=60−25
⇒x=35
Thus, the speed of car starting from A=x=35 km/hr and speed of car starting from B=y=25 km/hr.
Answer:
Distance=80km
let speed of Car A=x km/hr
let speed of Car B=y km/hr
Acc to ques
x-y=80/8
x-y=10--------(1)
also
x+y=80 × 60/80 (1 hr 20 min= 1+(20/60)=80/60)
x+y=60------(2)
adding (1) and (2)
x-y+x+y=70
2x=70
x=35
put x=35 in (1)
35-y=10
25=y
SPEED OF CAR A=35 km/hr
SPEED OF CAR B= 25 km/hr