Hi, please help me answer a,b,c,d, and e. The previous one did not answer all questions :( thanks.

4. On October 26, 2019, an archaeologist unearthed a radioactive specimen. Month later, he weighed the material and found out to be 180 pounds. A year later since last time he took its weight, only 84 pounds of the sample remains. Calculate: (Reference date will be the day the sample was unearthed and assume lyr= 360days and 1month=30days) a.) %decayed on November 26, 2019 b.) fraction of sample remains a year after Nov. 26,2019 c.) date (month day, year) at which half of the specimen decayed d.) time in years at which 90% of the original amount decayed. e.) approximate no. of years at which all the specimen will be depleted