Solve the Problem $\mathrm { n }$ Represents a 30 -Minute Interval

Multiple Choice

Solve the problem.
-Suppose that certain bacteria can double their size and divide every 30 minutes. Write a recursive sequence that describes this growth where each value of $\mathrm { n }$ represents a 30 -minute interval. Let a $1 = 490$ represent the initial number of bacteria present.

A) $a _ { n } = 2 a _ { 1 }$ for all values of $n$ .
B) $a _ { 1 } = 490 ; \quad a _ { n } = 2 a _ { n } + 1$ for $n > 1$
C) $\mathrm { a } _ { 1 } = 490 ; \mathrm { a } _ { \mathrm { n } } = 2 \mathrm { a } _ { \mathrm { n } - 1 }$ for $\mathrm { n } > 1$ .
D) $a _ { 1 } = 490 ; \quad a _ { n } = \frac { 1 } { 2 } a _ { n - 1 } \quad$ for $n > 1$