public boolean studentPaidLicense(Activity activity, Student student) {
		Calendar previousBillDate = Calendar.getInstance();
		previousBillDate.add(Calendar.MONTH, -1);
		Bill oldBill;
		if(activity.getLicense().equals(new BigDecimal(0))){
			return true;
		}
		try {
			oldBill = findBillByDate(student.getHouseHold(), previousBillDate);
		} catch (InstanceNotFoundException e) {
			return false;
		}
		for (BillLine billLine : oldBill.getBillLines()) {
			if ((activity.getName().compareTo(billLine.getConcept()) == 0)
					&& (billLine.getStudent().equals(student))) {
				return true;
			}
		}
		return false;

	}