Public class calculatepennies { // returns number of pennies if pennies are doubled numdays times public static long doublepennies(long numpennies, int numdays) { long totalpennies; /* your solution goes here */ if(){ } else { totalpennies = doublepennies((numpennies * 2), numdays - 1); } return totalpennies; } // program computes pennies if you have 1 penny today, // 2 pennies after one day, 4 after two days, and so on public static void main (string [] args) { long startingpennies; int userdays; startingpennies = 1; userdays = 10; system. out. println("number of pennies after " + userdays + " days: " + doublepennies(startingpennies, userdays)); } }