I rode a bicycle back and forth between the two points A and B, traveling at 15 kilometers per hour (km) on the way forth and 10 kilometers per hour (km) on the way back. It took 30 minutes longer to come back. Find the time it took to go forth.
10 30 60 [OP_DIV] [OP_MUL] 15 10 [OP_SUB] [OP_DIV]
var_a = 10
var_b = 30
var_c = 60
var_d = var_b / var_c
var_e = var_a * var_d
var_f = 15
var_g = 10
var_h = var_f - var_g
var_i = var_e / var_h
print(int(var_i))