opk3223256 opk3223256 09-02-2018 Mathematics contestada Which number is not in scientific notation? Select one: a. 11 ⋅ 10^21 b. 5.7 ⋅ 10^9 c. 3.1 ⋅ 10^−12 d. 1.67 ⋅ 10^−5