Here is 2nd Challenge for Python Practice 
Question 2:-
3 product enter than you show what is billning product and what is free product
2K < == 5%
2k - 5k == 10%
5K- Above == 20%
discount first calculate than count tax
total * 5/100
toatal * 10/100
total * 20/100

Solutions ==> 

a = int(input("Enter First Product Price : "))

b = int(input("Enter Second Product Price : "))

c = int(input("Enter Third Product Price : "))

def buy_get_one_free(p1,p2,p3):

free = 0

if b > a < c:

free += a

elif a > b < c:

free += b

else:

free += c

return free

print(f"Free Product is {buy_get_one_free(a,b,c)}")

total = a+b+c-(buy_get_one_free(a,b,c))

print(f"Total product Value : {total}")

def tax(t):

tax = 0

if total < 2000:

tax += 0

elif 4000 < total > 2000:

disc = (total * 5)/100

tax += disc

elif 4000 < total > 6000:

disc = (total * 10)/100

tax += disc

elif total > 6000:

disc = (total*20)/100

tax += disc

return tax

print(f"Your Discount Value is {tax(total)}")

print(f"Your Total Paid Amount is {total-tax(total)}")

Output ==> 

Enter First Product Price : 50000
Enter Second Product Price : 60000
Enter Third Product Price : 70000
Free Product is 50000
Total product  Value : 130000
Your Discount Value is 6500.0
Your Total Paid Amount is 123500.0