When building a house, the number of days required to build varies inversely with with the number of workers. One house was built in 29 days by 27 workers. How many days would it take to build a similar house with 9 workers?

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?