bacteria

[jonnysunn]

Lost with this question: my choice was D....

A scientist is studying bacteria whose cell population doubles at constant intervals, at which times each cell in the population divides simultaneously. Four hours from now, immediately after the population doubles, the scientist will destroy the entire sample. How many cells will the population contain when the bacteria is destroyed?

(1) Since the population divided two hours ago, the population has quadrupled, increasing by 3,750 cells.

(2) The population will double to 40,000 cells with one hour remaining until the scientist destroys the sample.

Official Answer:

SPOILER: C

[gvj]

I feel the answer is (A)

Here is why...

Say the point in time right now is T

Statement 1: Let X be the number of Bacteria at time T-2
Statement 1 also suggests that the number at T was 4X
and that 4X - X = 3750...

This would make 4X = 5000 at time T. Also the multiplication interval has to be 1 hr.

This would mean, at T+4 hrs the number of bacteria would be 80,000

Hence Statement 1 is sufficient.

Statement 2 gives us the number of bacteria at time T+3 but does not give us the interval hence it is insufficient...

[MAMA]

I feel the answer is (A)

Here is why...

Say the point in time right now is T

Statement 1: Let X be the number of Bacteria at time T-2
Statement 1 also suggests that the number at T was 4X
and that 4X - X = 3750...

This would make 4X = 5000 at time T. Also the multiplication interval has to be 1 hr.

This would mean, at T+4 hrs the number of bacteria would be 80,000

Hence Statement 1 is sufficient.

Statement 2 gives us the number of bacteria at time T+3 but does not give us the interval hence it is insufficient...

A is bvious but B is a trap.

agree with you.

[cinghal1]

i also vote for A - Official Answer must be wrong.

[surya167]

The answer should be D and not A alone

if we consider statement B, we find that, the populations doubles to 40,000 in 3 hours. And acc to the q, the population doubles in 4 hours. so the number of cells at that time should be 80,000.

So, A and B both are sufficient to give the answer
Hence D. Official Answer must be D

[surya167]

[spoiler:d]