Two cyclists start at the same corner and ride in opposite directions. One cyclist rides twice as fast as the other. In 3 hours, they are 81 miles apart. Find the rate of each cyclist.

Respuesta :

The rate of one cyclist is 9 miles per hour and other cyclist is 18 hours per hour, if the two cyclists start at the same corner and ride in opposite directions. One cyclist rides twice as fast as the other. In 3 hours, they are 81 miles apart.

Step-by-step explanation:

The given is,

               Two cyclists start at the same corner and ride in opposite directions

                One cyclist rides twice as fast as the other

                 In 3 hours, they are 81 miles apart

Step:1

                Let, X - Rate of one cyclist

                     2X - Rate of other cyclist

                     ( One cyclist rides twice as fast as the other )

Step:2

     Formula to calculate rate of cyclist,

   [tex]Distance between 2 cyclist = ( Rate of one cyclist + Rate of other cyclist ) (Hours)[/tex]

                                                                                .........................................(1)

     From the given values,

                                        [tex]81=(X +2X)(3)[/tex]

                                        [tex]81 = (3X )(3)[/tex]

                                        [tex]81=9X[/tex]

                                        [tex]X=\frac{81}{9}[/tex]

                                             = 9

                                        [tex]X = 9[/tex]

       From the X value,

                      Rate of one cyclist, X = 9 miles per hour

                  Rate of other cyclist, 2X = 2 × 9

                                                           = 18

                 Rate of other cyclist, 2X = 18 miles per hour

Step:3

            Check for solution,

               Distance covered by one cyclist = Rate of cyclist × Hours

                                                                      = 9 × 3 = 27 miles

             Distance covered by other cyclist = Rate of cyclist × Hours

                                                                      = 18 × 3 = 54 miles

             From equation (1),

                                                                  81 = 27 + 54

                                                                  81 = 81

Result:

             The rate of one cyclist is 9 miles per hour and other cyclist is 18 hours per hour, if the two cyclists start at the same corner and ride in opposite directions. One cyclist rides twice as fast as the other. In 3 hours, they are 81 miles apart.