David has $500 to buy CDs and DVDs. CDs cost $12 and DVDs cost $20. Which of these is a combination of CDs and DVDs that David can buy? (A) 5 CDs, 25 DVDs
(B) 10 CDs, 20 DVDs
(C) 15 CDs, 15 DVDs
(D) 35 CDs, 5 DVDs

Monica build a remote control toy airplane for science project to test the plane she launched it from the top of a building the plane travel a horizontal distance of 50 feet before landing on the ground a quadratic function which models the height of the plane in feet relative to the ground at a horizontal distance of x feet from the building is shown

Recall that the owner of a local health food store recently started a new ad campaign to attract more business and wants to know if average daily sales have increased. historically average daily sales were approximately $2,700. the upper bound of the 95% range of likely sample means for this one-sided test is approximately $2,843.44. if the owner took a random sample of forty-five days and found that daily average sales were now $2,984, what can she conclude at the 95% confidence level?

In a two-digit number the units' digit is 7 more than the tens' digit. the number with digits reversed is three times as large as the sum of the original number and the two digits. find the number.