Let x be a multiple of 7.

∴       The next two consecutive multiples of 7 are x + 7 and x + 7 + 7 (i.e. x + 14).

∴        Three consecutive multiples of 7 are: x, x+7 and x+14

          According to the condition,

                           x + (x+7) + (x+14) = 63

  ∴                                          3x + 21 = 63
     Transposing 21 to RHS, we have

                                              3x = 63 - 21 = 42

     Dividing both sides by 3, we have

                                           

or                                             x = 14


∴                                          x + 7 = 14 + 7 = 21

and                                     x + 14 = 14 + 14 = 28

    Thus, the three consecutive multiples of 7 are: 14, 21 and 28.