Anna has been studying a type of bacteria that triples every month. Originally, there were 4 bacterial cells. She wants to know how many there will be after 15 months. Which equation should she use?. . a15 = 4(3)(15). . a15 = 4(3)15. . a15 = 4(3)15 − 1. . a15 = 4(3)(15 − 1). @perl . @DarkBlueChocobo
Answer:
\(a(15)=4(3)^{15}\)
Explanation:
Given,
Original number of bacterial cell = 4,
Also, the number of bacterial cell triples every month,
So, the number of bacteria after one month = 3 × 4 = 4(3)
After two months = 3 × 4(3) = 4(3)²,
After three months = 3 × 4(3)² = 4(3)³,
......................................................... , so on,
Thus, the number of bacterial cell after 15 months,
\(a(x)=4(3)^x\)
For 15 months, x = 15,
Hence, the number of bacterial cells after 15 months,
\(a(15)=4(3)^{15}\)
Which is the required equation she should use.
Answer:
Option A
Explanation:
The initial number of bacteria's is equal to \(4\)
This number get tripled every month which means after one month the number of bacteria's will be \(4 * 3\)
After two months the number of bacteria's will be \((4 * 3)*3\)
After three months the number of bacteria's will be \(((4 * 3)*3)*3\)
i,e after three months total number of bacteria's is equal to \(= 4* (3)^3\)
Thus, after three months total number of bacteria's is equal to \(= 4* (3)^15\)
Hence, option A is correct