Question

29. Distance between two places A and B is 350 km. Two cars start simultaneously from
A and B towards each other and the distance between them after 4 hours is 62 km. If
speed of one car is 8 km/h less than the speed of other car, find the speed of each car​

Answer 1

Given :

• Distance between two places A and B = 350 km / hr

• After 4 hours = 62 km / hr

• Speed of One Car = 8 km / hr less than Another

To find :

• Speed of Each Car

According to the question :

Let the Speed of Car C1 = x km / hr

Speed of Car C2 = ( x - 8 ) km / hr

So,

⟹ ( x × 4 ) + ( x - 8 ) × 4 = 350 - 62

⟹ 4x + [ ( 4 × x ) - ( 4 × 8 ) ] = 350 - 62

⟹ 4x + ( 4x - 32 ) = 288

⟹ 8x - 32 = 288

⟹ 8x = 288 + 32

⟹ 8x = 320

⟹ x = 320 / 8

⟹ x = 40 km / hr

We found :

➳ Speed of Car C1 = 40 km / hr

➳ Speed of Car C2 = ( x - 8 ) = ( 40 - 8 ) = 32 km / hr

So, It's Done !!

Answer 2

${ \bf{ \red{ \underline{ \purple{ \underline{Given \: data }}}}} : - }$

• Distance between two places A and B is 350 km.
• Two cars start simultaneously from A and B towards each other and the distance between them after 4 hours is 62 km.
• Speed of one car is 8 km/h less than the speed of other car.

${ \bf{ \red{ \underline{ \purple{ \underline{Solution}}}}} : - }$

Let, speed of first car be x and speed of second car be y.

{Now, according to given}

→ Speed of first car = {y - 8}km/h .....[1]

→ Speed of second car = y km/hr

→ The speed of first car with second car

= {y - 8 + y } km/hr ......[2]

Distance between two places A and B is 350 km. and after 4 hour distance between them is 62 km.

So, we know that

→ Distance covered by first car and second

car in 4 hour = {350-62} km

→ Distance covered by first car and second

car in 4 hour = 288 km .....[3]

Now, we use formula of speed:-

${ \red{ \dashrightarrow{ \purple{ \bf{Speed = \frac{Distance }{Time} }}}}}$

{From [ 3 ]}

Speed of first car with second car :-

${ \red{ \dashrightarrow{ \purple{ \bf{Speed = \frac{288 }{4} }}}}}$

${ \red{ \dashrightarrow{ \purple{ \bf{Speed = 72 \: km/hr }}}} \: \: \: \: \: \: ....[4]}$

Hence, speed of first car with second car is 72 km/hr.

Now, from [1] & [4]

→ y - 8 + y = 72

→ y + y - 8 = 72

→ 2y - 8 = 72

→ 2y = 72 + 8

→ 2y = 80

→ y = 80/2

→ y = 40

Hence,

→ Speed of second car = y km/hr

→ Speed of second car = 40 km/hr

Now, put value of y in eq. [1]

→ Speed of first car = {y - 8}km/h

→ Speed of first car = {40 - 8}km/h

→ Speed of first car = 32 km/h

Hence, speed of first car is 32 km/hr and Speed of second car is 40 km/hr.