Tech A says that mass airflow sensors determine mass airflow based on engine speed and manifold pressure. Tech B says that some airflow sensors use a hot wire to determine mass airflow. Who is correct

At 12 noon, the count in a bacteria culture was 400; at 4: 00 pm the count was 1200 let p(t) denote the bacteria cou population growth law. find: (a) an expression for the bacteria count at any time t (b) the bacteria count at 10 am. (c) the time required for the bacteria count to reach 1800.