bryanownsu
Jun 20, 2010, 12:58 AM
Clement and Cedric took part in the 21 km Army Half Marathon race. Clement ran at an
average speed of x km/h. Cedric’s average speed was 5 km/h slower than Clement and
he completed the race 30 minutes later.
(a) Write down, in terms of x, the time taken for Clement to complete the race.
(b) Write down, in terms of x, the time taken for Cedric to complete the race.
(c) Form an equation in x and show that it reduces to x to the power of 2-5x-210=0 .
(d) Solve the equation x to the power of 2-5x-210=0, giving your answers correct to 2 decimal
places.
(e) Hence find, in hour and minutes, the time it took Clement to complete the race.
average speed of x km/h. Cedric’s average speed was 5 km/h slower than Clement and
he completed the race 30 minutes later.
(a) Write down, in terms of x, the time taken for Clement to complete the race.
(b) Write down, in terms of x, the time taken for Cedric to complete the race.
(c) Form an equation in x and show that it reduces to x to the power of 2-5x-210=0 .
(d) Solve the equation x to the power of 2-5x-210=0, giving your answers correct to 2 decimal
places.
(e) Hence find, in hour and minutes, the time it took Clement to complete the race.