please answer

Problem [4 marks] : A sample of a radioactive substance is decaying exponentially, with an initial mass of 1800 milligrams. After 5 months, the mass has decreased to 600 milligrams. (a) What will the mass of the sample be after 10 months? (b) What is the half-life of the sample (in months)? Problem #5(a): In 2 (A) 5 In 3 (B) (C) 2 (D) " ( E) - (F) 5 In 2 In 3 Problem #5(b): Select @ T Part (b) choices. Save Your work has been saved!_(Back to Admin Page) Problem Ary Consider the function f(x) = 4 arctan(x + 7). [4 marks] (a) What is the domain of f? (b) What is the range of f? (A) (-1, 7) (B) (-1+ 7, 15+ 7) (C)(-, 8 ' 3) (D) (-1 - 7, 2- , " - 7) (E) (-2J, 271 ) ( F) (-00, 00) Problem #6(a): Select @ 1 Part (a) choices. (A) (-1, ) (B) (-21, 250) (C) (-7+7, 15 + 7) (D) (-12-7, 51-7) (E) (-00,00) (F) (- 2, 2, Problem #6(b): Select @ T Part (b) choices