Places A and B are 120 km apart on a highway. One car starts from A and another from B at the same time. If the cars travel in the same direction (at different speeds) they meet in 4 hours. If they travel towards each other , they meet in 2 hours" Based on the above situation , assuming the speed of the first car be "x" kmph and second car be "y" kmph respectively , answer the following questions 1 to 4 Q1 What is the equation when both cars are travelling in the same direction ?
Answers
Answer:
Let the speed of car I=xkm/hr
And the speed of car II=ykm/hr
Car I starts from point A and Car II starts from point B.
Let two cars meet at C after 6h.
Distance travelled by car I in 6h=6xkm
Distance travelled by car II in 6h=6ykm
since, they are travelling in same direction, sign should be negative 6x−6y=120
⇒x−y=20…(i)
Now, Let two cars meet after 1 hr 12 min 1hr 12min=1+
60
12
=
5
6
hr
since they are travelling in opposite directions, sign should be positive.
5
6
x+
5
6
y=120
⇒6x+6y=120×5
⇒x+y=100…(ii)
On adding (i) and (ii) , we get x−y+x+y=20+100
⇒2x=120
⇒x=60
Putting the value of x=60 in Eq. (i), we get 60−y=20
⇒y=40
So, the speed of the two cars are 60km/h and 40km/hr respectively.
Answer:
the speed of car I=xkm/hr
And the speed of car II=ykm/hr
Car I starts from point A and Car II starts from point B.
Let two cars meet at C after 6h.
Distance travelled by car I in 6h=6xkm
Distance travelled by car II in 6h=6ykm
since, they are travelling in same direction, sign should be negative 6x−6y=120
⇒x−y=20…(i)
Now, Let two cars meet after 1 hr 12 min 1hr 12min=1+
60
12
=
5
6
hr
since they are travelling in opposite directions, sign should be positive.
5
6
x+
5
6
y=120
⇒6x+6y=120×5
⇒x+y=100…(ii)
On adding (i) and (ii) , we get x−y+x+y=20+100
⇒2x=120
⇒x=60
Putting the value of x=60 in Eq. (i), we get 60−y=20
⇒y=40
So, the speed of the two cars are 60km/h and 40km/hr respectively.