Discounted Lifetime Value

Problem

Compute the discounted lifetime value: sum over periods t = 0, 1, ... of revenues[t] / (1 + discount_rate)^t.

Empty input returns 0.0.

Hint

Period 0 revenue is not discounted; later periods are divided by (1 + rate)^t.

case 1

in: [[100,100,100],0.1]

expected: 273.55371900826447

case 2

in: [[0,100],0.1]

expected: 90.9090909090909

case 3

in: [[50],0]

expected: 50

case 4

in: [[100],1]

expected: 100

Starter codePython

def discounted_ltv(revenues, discount_rate):
    # Your code here
    pass

4 test cases · run your code against them in the editor