CSC 110 Lab Week 4

Calculating Investments

In this short project, you will calculate how many years it takes for an account balance to reach an investment goal.

Name the program investment.py. Make sure that gradescope gives you the points for passing the test cases.

Description of the problem

Here’s the problem to solve:

Imagine you have X amount of dollars in an investment account that earns 5% interest per year. How long (in years) does it take for the account balance to be times Y the original investment?

# X amount of dollars is $10,000
initial_amount = 10000

# times Y is 2
goal_of_investment = 2

message = investment_years(initial_amount, goal_of_investment)
print(message)

The investment of $10,000 will be 2 times larger in 15 years.

Development strategy

You will need to use a while loop to solve this problem. You need to calculate what the goal amount is, and you will calculate how much each passing year accrues until you get to the goal.

You will also need to create a year variable to count how many years it takes to achieve the goal. Remember to increment year with every iteration.

Calculate the interest (multiply balance by 0.05) and the balance (add interest to it) in each iteration as well.

Test cases

def main():
    # X amount of dollars is $10,000
  initial_amount = 10000

  # times Y is 2
  goal_of_investment = 2

  message = investment_years(initial_amount, goal_of_investment)
  print(message) 
  # The investment of $10,000 will be 2 times larger in 15 years.

  print(investment_years(50000, 10))
  # The investment of $50,000 will be 10 times larger in 48 years.

main()