The current age of 'N' is 25% more than the current age of 'M'. The present age of 'P' is the average of the present ages of 'M' and 'N'. Three years from now, the combined age of 'M' and 'P' will be 40 years. If the present age of 'N' is given as 'b', determine the age of 'P' after b/4 years from now.