Question

Kim and Om are travelling from point A to B, which are 400 km apart, travelling at a certain speed Kim takes one hour more than Om to reach point B. If Kim doubles her speed she will take 1 hour 30 minutes less than Om to reach point B. At what speed was Kim driving from point A to B?​

Answer 1

Step-by-step explanation:

Let the speed of Kim be a and that of Om be b

Distance between point A and B = 400 km

Then,

400a−400b=1

Let,

1a=x and 1b=y400x−500y=1.....(i)

Speed of km doubles and she will take lets time i.e., 1 hr 30 min than 0 metre

Again,

400b−4002b=32∴400y−200x=32800y−400x=3

Solving (i) and (ii), we get

400x−400y=1−400x+800y=3400y=4∴y=4100=1100 km∴b=100 kmNow,400a−400100=4or, 400a∴a=80 kmph

thank you !!!

Answer 2

Answer:

A ______________ B

400 km

let speed of Kim = u kmh

######### Om = u kmh

case 1 : 400÷u — 400÷u = 1

case 2 : 400÷u — 400÷2u = 3÷2. now add both cases

suppose u = x after adding both you get 80 answer if x = 80 then u = 80

80 kmh is the speed of Kim

I hope it helps