13 April, 12:15

# 17,280 meal wormsc) 45 daysYour baby brother has an ear infection. The doctor said there areprobably 50,000,000 bacteria in his left ear. The penicillin the doctorprescribed will kill 1/10 of the bacteria every 6 hours. How many bacteriawill be in your brother's ear in ...Cremain)a) 1 dayb) 5 daysc) 1 weekd) 3 hours

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1. 13 April, 12:33
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a) 30 000 000

b) - 100 000 000

c) - 160 000 000

d) 27 500 000

Step-by-step explanation:

You want to know how many bacteria are killed every 6 hours which is 1/10 so 50 000 000:10 = 5 000 000 every 6 hours.

a) how many times does 6 hours fit in 1 day) 24:6=4 so 4*5 000 000 = 20 000 000 so then you subtract that from 50 000 000 because you want to know what remains which means 30 000 000 bacteria remain.

b) we already calculated 1 day so 30 000 000*5=150 000 000. Then you subtract that from the 50 000 000. 50 000 000 - 150 000 000 = - 100 000 000

c) 1 day * 7 = 30 000 000*7 = 210 000 000 - 50 000 000 = - 160 000 000

d) 5 000 000:2 = 2 500 000 = 30 000 000 - 2 500 000 = 27 500 000 6 hours divided by 2 equals 3 hours so you also divide the bacteria by 2.