1. Samantha invested $880 in an account paying an 2. Element X is a radioactive isotope such that every 25 interest rate of 3.1% compounded continuously. years, its mass decreases by half. Given that the initial Assuming no deposits or withdrawals are made, how mass of a sample of Element X is 90 grams, how long long would it take, to the nearest tenth of a year, for the would it be until the mass of the sample reached 55 value of the account to reach $1,270? grams, to the nearest tenth of a year