module vat_module
contains
real function vat(rate,x)
implicit none
real, intent(in)::rate, x
   vat = rate/100*x
end function vat
end module vat_module

program ch1207a
use vat_module
implicit none
real:: cost, total_cost, vat_rate
      print*,'input current vat rate'
      read*,vat_rate
      print*,'input base cost of item'
      read*,cost
      total_cost = cost + vat(vat_rate,cost)
      write(*,100)total_cost
      100 format('total cost inc. vat = ',f6.2,' pounds')
end program ch1207a