The half-life of radium is 1690 years. If 40 grams are present now, how much will be present in 980 years?

Part a : solve -vp + 40 < 65 for v part b : solve 7w - 3r = 15 for r show your work .

You got a job selling magazines door-to-door. you are paid $100 per day plus $1.50 for each magazine you sell. which recursive formula models this situation?

Weekly wages at a certain factory are normally distributed with a mean of $400 and a standard deviation of $50. find the probability that a worker selected at random makes between $450 and $500