A factory begins the day with 6,000 packaged light bulbs. The machines in the factory can package 1,200 light bulbs every hour for the next 5 hours. ​ ​
​The initial value of this function is

and the rate of change is

Harry owes the bank money. to repay his debt, he paid $150 back to the bank each month. after 10 months, his remaining debt was $6900. what was the original amount of harry's debt? how long did it take harry to pay back his entire debt?