Astationary shop has a sale on address books and calendars. two of the address books and one calendar cost a total of $10. one of the address books and three calendars cost a total of $15. how much does one calendar cost ? a) $6 b)$3 c)$1 d) $4

Situation: . find the substance's half-life, in days. round your answer to the nearest tenth. a 11 gram sample of a substance that's used to treat thyroid disorders has a k. value of 0.1247. enter the correct answer n - noekt done no - initial mass (at time t = 0) n - mass at timet k a positive constant that depends on the substance itself and on the units used to measure time t= time, in days