50 uL of a sample is pipetted into 100 uL of diluent in a test tube. The concentration of the tube is 1000 ng/ml (A). You will perform a serial dilution, taking 50 uL from the first tube and transferring
into 100 uL of diluent, into three more tubes. What is the final concentration of the third tube?

Mr. will, a 67-year-old patient, is postoperative day 2 after a coronary artery bypass graft operation to revascularize his coronary arteries that were significantly blocked. he has a midline incision of his chest and a 7-inch incision on the inner aspect of his right thigh where a saphenous vein graft was harvested and used to vascularize the blocked coronary artery. the surgeon ordered oxycodone 5 mg every 4 hours prn for moderate pain and oxycodone 10 mg every 4 hours prn for severe pain. a. considering the patient's age, what medication administration considerations should the nurse incorporate into the pain management plan and why? b. what measures should the nurse provide the patient to prevent adverse effects of analgesic agents from occurring? c. what nonpharmacologic pain management methods should the nurse teach to mr. will to assist with pain management?