CUTICAJ)
A family decides to travel from Singapore to Kuala
Lumpur, which are 315 km apart. The average speed
of an aeroplane is 350 km/h more than the speed of
a car. Let the average speed of the car be x km/h.
(i) Write down an expression, in terms of x, for the
number of hours taken by the family if they
choose to travel by aeroplane.
If they choose to travel by aeroplane instead of by car,
they will be able to reach Kuala Lumpur 3 hours and
15 minutes earlier.
(ii) From the information given, formulate an equation
in x and show that it reduces to
13x2 + 4550x – 441 000 = 0.
(iii) Solve the equation 13x2 + 4550x – 441 000 = 0,
giving both your answers correct to 2 decimal places,
(iv) Find the time taken by the family to travel by
aeroplane, giving your answer correct to the
nearest minute.

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