Let's assume that the scheduled speed of the train is x km/h.
The train travels a distance of 240 km, so the actual travel time at a speed of (x - 10) km/h is given by the equation:
240 / (x - 10)
Since the train is late by 48 minutes, or 48/60 hours, the actual travel time can be expressed as:
240 / (x - 10) = (240 / x) + 48/60
To simplify the equation, let's convert the minutes to hours:
48/60 = 4/5 hours
240 / (x - 10) = (240 / x) + 4/5
To combine the fractions, let's find a common denominator:
240 / (x - 10) = (240 / x) + (4/5) * (x / x)
240 / (x - 10) = (240 / x) + 4x / (5x)
To simplify the equation further, let's clear the fractions by multiplying through by x(x - 10):
240x = 240(x - 10) + 4x(x - 10) / 5
240x = 240x - 2400 + (4x^2 - 40x) / 5
Multiplying through by 5 to simplify the equation:
1200x = 1200x - 12000 + 4x^2 - 40x
Rearranging the equation to isolate the terms:
4x^2 - 40x = -12000
Dividing through by 4 to simplify:
x^2 - 10x = -3000
Moving all terms to one side to form a quadratic equation:
x^2 - 10x + 3000 = 0
This quadratic equation can be factored as:
(x - 60)(x - 50) = 0
Setting each factor equal to zero:
x - 60 = 0 or x - 50 = 0
Solving for x:
x = 60 or x = 50
Since the train cannot travel at a speed of 60 km/h and be late, the scheduled speed of the train should be 50 km/h.
