You are trying to get 2 balls out of a box containing a red ball, a blue ball, a black ball, and a yellow ball. How many ways are there for balls can be drawn if allowing duplication? However, the order in which the balls are retrieved is not considered.
[OP_LIST_SOL] red blue black yellow [OP_LIST_EOL] [OP_LIST_LEN] 2 [OP_ADD] 1 [OP_SUB] 2 [OP_COMB]
var_a = 'red'
var_b = 'blue'
var_c = 'black'
var_d = 'yellow'
list_a= []
if "/" in str(var_d):
    var_d = eval(str(var_d))
list_a.append(var_d)
if "/" in str(var_c):
    var_c = eval(str(var_c))
list_a.append(var_c)
if "/" in str(var_b):
    var_b = eval(str(var_b))
list_a.append(var_b)
if "/" in str(var_a):
    var_a = eval(str(var_a))
list_a.append(var_a)
list_a.reverse()
var_e = len(list_a)
var_f = 2
var_g = var_e + var_f
var_h = 1
var_i = var_g - var_h
var_j = 2
var_k = 1
var_i = int(var_i)
var_j = int(var_j)
for i, elem in enumerate(range(var_j)):
    var_k = var_k * (var_i-i)
for i, elem in enumerate(range(var_j)):
    var_k = var_k / (i+1)
print(int(var_k))