Rohit donated 1/5 of his monthly income to an Non-Government organisation(NGO) working for the education of the girl child,spent 1/4 of his salary on food,1/3 on rent and 1/15 on other expenses.He is left with Rs.9000.Find Rohit's monthly salary.(7th class math)

Rohit donated 1/5 of his monthly income to an Non-Government organisation(NGO) working for the education of the girl child,spent 1/4 of his salary on food,1/3 on rent and 1/15 on other expenses.He is left with Rs.9000.Find Rohit's monthly salary.(7th class math)

Solution:        Let Rohit monthly salary = x

                            Donation of NGO =x/5

                         Amount spent for food =x/4

                                                    Rent =x/3

                                    other expenses =x/15

                                    Salary Left = Rs.9000

                      According to the problem given,

                         x-(x/5+x/4+x/3+x/15) = 9000

                         x-(_12x+15x+20x+4x_) = 9000

                                           60

                                                 x-51x/60 = 9000

                                              _60x-51x_ = 9000

                                                       60

                                                        9x/60 = 9000

                                                             x = 9000 x 60/9

                                                             x = 60000

                         Therefore,

                                        Rohit monthly Salary = Rs.60000