At first, Ravi had $200 more than Vincent. He gave 40% of his money to Vincent. Vincent then gave 25% of his money to Ravi. In the end Vincent had $68 more than Ravi. How much did Vincent give Ravi?

Solution:-

Let Vincent has x dollars

Ravi has money = $ 200  + x

now,

Ravi gave 40% of money to Vincent

so , Rave gave moeny = 0.4 * (200 + x)

                                 = 80 + 0.4 x

and ravi has money = 200 + x - 80 - 0.4x

                             =  120  + 0.6x

vincent has money = x + 80 + 0.4 x

                            = 80 + 1.4 x

now, Vincent gave 25 % of money to Ravi

so Vincent gave = 0.25 * (80 + 1.4x)

                        = 0.35x + 20

so Vincent has money = 80 + 1.4x - 0.35x - 20

                                = 1.05x + 60

and Ravi has money  = 120+ 0.6 x + 0.35x + 20

                                = 140 + 0.95x

so now according to questions,

Vincent had $68 more than Ravi 

so , 140 + 0.95x - 68 = 1.05x + 60

so x = 120

ans so Vincent gave money to Ravi = 0.35x + 20

                                                  = 62 $