Do you want the catholic answer or do you just want a general answer, because it could be an opinion.
Im not sure but if you think of it, the one that you didn't put any salt is a independent variable because it doesn't really rely on anything it doesn't have salt. The Dependent variable would be the 2nd and the 3rd cup because it doesn't have much salt but the 4th cup has lots of salt so its basically controlled. Hope it helps !
Answer:
The correct answer is 4,960,000
Explanation:
If a yeast cell divides into two yeast cells in 120 minutes that means a yeast cell needs 2 hours to get double. So according to the question 2 hours ago a yeast colony consisted of 310,000 cells that means the present colony should have 620,000 cells.
So after six hours from now, this population will divide three times in six hours because the generation time of yeast cell is 2 hour and each time the number of cells will double.
Therefore, in first time the number will increase to 1,240,000(620000*2), the second time the number will increase to 2,480,000(1240000*2) and after final division, the number will be 4,960,000(2480000*2).
Therefore after 6 hours from now, the approximate number of yeast cells will be 4,960,000.