1. Iodine-131 is tone of the most commonly used radioactive isotopes of iodine. It is used to treat hyper- thyroidism and some kinds of thyroid cancer. (a) Iodine-131 has a half-life of about 8 days. Find an expression for I(t), the mass of Iodine-131 remaining after t days, in terms of t and Io, the initial mass of Iodine-131 present at time t = 0. (b) If a dose of 0.9 mg of Iodine-131 is administered, how much is still present after 24 hours? (c) How much Iodine-131 is present after one week? Does your answer make sense?

Question 2: When John started his first job, his first end-of-year salary was $82,500. In the following years, he received salary raises as shown in the following table. Fill the Table: Fill the following table showing his end-of-year salary for each year. I have already provided the end-of-year salaries for the first three years. Calculate the end-of-year salaries for the remaining years using Excel. (If you Excel answer for the top 3 cells is not the same as the one in the following table, your formula / approach is incorrect) (2 points) Geometric Mean of Salary Raises: Calculate the geometric mean of the salary raises using the percentage figures provided in the second column named “% Raise”. (The geometric mean for this calculation should be nearly identical to the arithmetic mean. If your answer deviates significantly from the mean, it's likely incorrect. 2 points)   Starting salary % Raise Raise Salary after raise 75000 10% 7500 82500 82500 4% 3300…

d₁ ≥ ≥ dn ≥ 0 with di even. di≤k(k − 1) + + min{k, di} vi=k+1 T2.5: Let d1, d2,...,d be integers such that n - 1 Prove the equivalence of the Erdos-Gallai conditions: for each k = 1, 2, ………, n and the Edge-Count Criterion: Σier di + Σjeл(n − 1 − d;) ≥ |I||J| for all I, JC [n] with In J = 0.