2 Money in my savings account earns interest at 10%

annual rate. Each time I go to the bank, I waste 15 minutes in line. My time is worth $10 per hour. During each year, I need to withdraw $10,000 to pay my bills.

a How often should I go to the bank?

b Each time I go to the bank, how much money should I withdraw?

c If my need for cash increases, will I go to the bank more often or less often?

d If interest rates rise, will I go to the bank more often or less often?

e If the bank adds more tellers, will I go to the bank more often or less often?