Lisa is 4 years older than three times her brother sammy's age. let 's' represent sammy's age and 'l' represent lisa's age.

which expression represents lisa's age?

• l = s + 4

• l = 3s

• l = 3s + 4

• l = 4s + 3

The number of revolutions of two pulleys is inversely proportional to their diameters. if a 24-inch diameter pulley making 400 revolutions per minute is belted to an 8-inch diameter pulley, find the number of revolutions per minute of the smaller pulley.

Kelly is a salesperson at a shoe store, where she must sell a pre-set number of pairs of shoes each month. at the end of each work day the number of pairs of shoes that she has left to sell that month is given by the equation s=300-15x , where s is the number of pair of shoes kelly still needs to sell and x is the number of days she has worked that month. what is the meaning of the number 300 in this equation

Stephen thublin invests $1,000,000 in a 45-day certificate of deposit with 6.55% interest. what is the total interest income from the investment?