Question

A car covers a distance of 400 km at a certain speed. had the speed been 12km/hr more,the time taken for the journey would have been 1 hour 40 minutes less. find the original speed of the car.

Answer 1

the original speed of the car you can see in the calculator virus type in Internet you will get it I am not here to tell every single answer

Answer 2

$\Large{\textbf{\underline{\underline{According\;to\;the\;Question}}}}$

Here,

Assume,

Original speed be p km/hr

Also,

t (time) = 400/p

Extended speed = (p + 12) km/h

Situation,

400/p - 400/p + 12 = 1(40/60)

400p + 4800 - 400p/p(p + 12) = 1(2/3)

4800/p(p + 12) = 5/3

5p² + 60p - 14400 = 0

p² + 12p - 2880 = 0

p² + 60p - 48p - 2880 = 0

p(p + 60) - 48(p + 60) = 0

(p + 60)(p - 48) = 0

p = -60 or 48 (Negative value is not applicable)

p = 48 km/h

Therefore,

Original speed is 48 km/h