Question

The sequence below shows the amount of bacteria that occurs after each hour:4, 12, 36, 108,Which formula can be used to determine the amount of bacteria in the next hour, NEXT, if the number of NOW bacteria is known?

Answer 1

The first term is, 4.

The second term is, 12.

That is,

$12=4\times3$

The third term is 36. That is,

$36=12\times3$

Similarly forth term 108 can be written as,

$108=36\times3$

Therefore, the sequence is,

$4,\text{ 3}\times4=12,3\times12=36,3\times36=108,\ldots$

Therefore, the next term will be, 108 x 3. That is,

$\text{NEXT}=3\times NOW$

OPtion a is correct.