Need Help!!

You are asked to create a plot of bank account balance vs time in days, assuming that on Day 1 the balance is $1000 and on Day 2 10.0% of X the balance is withdrawn, leaving $900 at the end of Day 2. Likewise on Day 3 another 10.0% of the previous day's balance is withdrawn and so on. Assume 10.0% of the previous day's balance is withdrawn each day. Construct the balance vs time (in number of days), for 30 days. How many days does it take to go from $500 to $250? This represents a second half life of the account. You are asked to create a plot of bank account balance vs time in days, assuming that on Day 1 the balance is $1000 and on Day 2 10.0% of X the balance is withdrawn, leaving $900 at the end of Day 2. Likewise on Day 3 another 10.0% of the previous day's balance is withdrawn and so on. Assume 10.0% of the previous day's balance is withdrawn each day. Construct the balance vs time (in number of days), for 30 days. How many days does it take to go from $500 to $250? This represents a second half life of the account