Question

3/7 of the spectators were in covered place while 12000 in open . Find total number of spectators

Answer 1

Let the total no. of spectators be x.
so according to the question - 
                                        
                                    3x/7 + 12000=x
                              =>  3x+84000 = 7x
                              =>  7x-3x  = 84000
                             =>         4x=84000
                              =>         x=84000/4           
                                            =21000
 therefore there are 21000 spectators.

Answer 2

21000 spectors....................................................................................