Each day, mr. ling has a boy and a girl summarize the assignment for the day. there are 8 boys and 9 girls in his group. in how many different ways can the teacher select the two students? (see example 4.) ways

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?