Ruby on Rails

@mem = []  @tran = Transport.find_all_by_month_and_vehicle(date,vehicle)  tran.each do |t|    @mem << [Student.find_by_id(t.mem_id), t.transport_date, vehicle.no] if t.mem_type=="Student"    @mem << [Employee.find_by_id(t.mem_id), t.transport_date, vehicle.no] if t.mem_type=="Employee"  end

And in the view page I am looping and displaying it as

@mem.each do |m|    <tr>              <td><%= link_to m[0].first_name} %></td>              <td > <%= m[0].age %></td>              <td id="date"> m[1] </td>              <td id="vehicle"> m[2] </td>    </tr>  <%end%>

But I am getting duplicate entries in the table... So I neeed to remove duplicates and display only unique values.. I tries doing 
  @mem << [Student.find_by_id(t.mem_id), t.transport_date, vehicle.no].uniq! if t.mem_type=="Student".. But it is not working.. Please help