Your baby brother has an ear infection. The doctor said there are probably 50,000,000 bacteria in his left ear. The penicillin that the doctor prescribed will k**l 7% of the bacteria every 6 hours. He is contagious until there are fewer than 100,000 bacteria. How long until he is no longer contagious?
100,000 =50,000,000 * 0.93^n
Divide both sides by 50,000,000
0.002 =0.93^n
Take the log of both sides
n =log(0.002) / log(0.93)
n=85.6 hours = ~86 hours - when the baby is no longer contagious, or just over 3 ½ days.
+1262 so it is the equation 50000000*(0.93)^x<100000 so the answer is 23 becuase 100000/50000000 is about 0.02 and 0.02 is greater then 0.93^23 and the answer is \(23\)
+37146 Well, first of all 100 000 / 50 000 000 = = . 00 2
so .002 > .9386.63523174
so x = 85.635 TIME periods each period is six hours
* 6 = 513 .81 hours = 21.4 days
