Question

please solve for brainliest award.

Answer 1

Total distance a man travels = 600 Kms
Total time taken = 8 h 40min = 8 40/60= 26/3h
Let the speed of train be X km/h
& the speed of car be Y km/h
CASE 1.
If he traveled 320 km by train and remaining 280 Kms by car he has taken 26/3h
The equation :
320/X + 280/Y = 26/3 ................ (A)
(320Y + 280X) / XY = 26/3
Cross multiply then we get,
960Y + 840X = 26XY
Divide by 2 we get,
480Y + 420X = 13XY .............. (1)


CASE 2.
If he traveled 200 km by train and remaining 400 Kms by car he has taken 9h 10 min = 9 1/6
= 55/6h
The equation :
200/X + 400/Y = 55/6 ............... (B)
(200Y + 400X) / XY = 55/6
Cross multiply then we get,
1200Y + 2400X = 55XY
Divide by 5 we get,
240Y + 480X = 11XY .............. (2)

Equate Y by multiply eq (2) by 2, we get
480Y + 960X = 22XY .............. (2'')

Subtract (1) from (2'') we get,
(480-480)Y + (960 - 420)X = (22 - 13)XY
540X = 9XY
Divide by X
540 = 9Y
Y = 540/9
Y = 60
SPEED OF CAR = 60 km/h

Subsitute Y value in (2'') or (1). We will put in (2'') we get,
(480x60) + 960X = (22x 60)X
(960 - 1320)X = - 28800
- 360X = - 28800
X = 28800/360
X = 80

SPEED OF TRAIN = 80 km/h