In considering the origin of cells, why do biologists focus on the origin of the cell membrane

In terms of origin of cells, the reason as to why biologists has focused more on the origin of the plasma membrane because the plasma membrane has the capability of regulating of what comes in and out of the cell—like which substances enters and exits in it.

9.9 years

a = p(1 + rt) . . account balance after time t at rate r starting with principal p

3000 = 2500(1 + 0.0202t) . . filling in the given numbers

1.2 = 1 + 0.0202t . . divide by 2500

0.2 = 0.0202t . . . subtract 1

0.2/0.0202 = t ≈ 9.901

it will take about 9.9 years for the account balance to reach $3000.