Question

***Will mark all right answers brainliest*** A certain type of bacteria is being grown on a Petri dish in the school’s biology lab. Inez does some measurements and determines that the area of the bacteria covering the Petri dish is doubling each day. She started the bacteria colony on February 9 and predicts that it will cover the entire Petri dish by February21 . If 100% of the Petri dish is covered after 12 days have passed, what percentage was covered on the starting day? Use your equation from part (b) plz explain

Answer 1

Answer:

0.0244%

Step-by-step explanation:

A = p(1 + r)^t

The future amount is 100, for 100 percent. From February 9 to February 21, there are 12 days. The rate of growth is 100% since the amount doubles each day. t = 12, for 12 days. p = beginning percentage.

100 = p(1 + 1)^12

log 100 = log [p(1 + 1)^12]

2 = log p + 12 log 2

log p = 2 - 12 log 2

p = 10^(2 - 12log 2)

p = 0.0244

Answer 0.0244%

Answer 2

Answer:

On day 0 (starting day), the percentage of petri dish occupied by bacteria was 2.44%

Step-by-step explanation:

Rate of growth = 2  (i.e. doubles every day)

Petri dish was filled to 100% on day 12.

Let

P(0) = percentage of Petri dish occupied on day 0, then

equation of percentage a  function of time in x days

P(x) = P(0)*r^x  ......................(1)

where

100% = P(12) = p(0) * 2^12 = 4096 P(0)

=>

P(0) = 100% / 4096 = 0.0244%

Next, to find percentage on February 14 (Valentine's day!)

Day 0 is February 9, so February 14 is the fifth day, so x=5.

Substitute x=5 in equation (1) above,

P(x) = P(0)*r^x  

P(5) = P(0)*2^5

P(5) = 0.0244*2^5 = 0.0244*32 = 0.781%

Ans. the 0.781% of the petri dish was filled with bacteria after 5 days on February 14th.