A person buys q1, q2, q3 and q4 units of four goods whose prices per unit are, re- spectively, $1, $2, $3 and $4. What is the total expenditure? What will be the total expenditure if the prices change to $4, $3, $2 and $1 per unit respectively?

Abank manager wants to encourage new customers to open accounts with principals of at least $2 comma 500. he decides to make a poster advertising a simple interest rate of 3%. what must the principal be if the bank manager also wants to advertise that one can earn $10 the first month? can the poster correctly say, "open an account of $2 comma 500 and earn at least $10 interest in 1 month! "?