Majoo !
a scientist running an experiment starts with 100 bacteria cells. these bacteria double their population every 15 hours. find how long it takes for the bacteria cells to increase to 300. use the formula , where is the original number of bacteria cells, is the number after t hours, and d is the time taken to double the number.
it takes hours for the number of bacteria to increase to 300.

22 1/2

Step-by-step explanation: The scientist starts off his experiment with only 100 bacteria cells okay. It takes 15 hours for the bacteria cells to double there population. Meaning 15 hours=200 bacteria cells. So what you have to do know is find out what to do next which is count 15 in half. After that step you should get 7 1/2. know what you do is add 15+7 1/2= 22 1/2. meaning 22 1/2 is your answer.  

distance covered by pamela in 9 l of fuel = 99km

let us apply unitary method here.

distance covered by pamela in 1 l of fuel =99/9 =11 km

now let us find distance covered by pamela if she has 12 l of fuel.

distance covered in 12 l = distance covered in 1 l of fuel * 12

we know that distance covered by here in 1 l is 11 km.

so distance covered in 12 l of fuel = 11*12 = 132 km.