1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Semmy [17]
3 years ago
8

A sample of bacteria is decaying according to a half-life model. If the sample begins with 700 bacteria, and after 10 minutes th

ere are 140 bacteria, after how many minutes will there be 40 bacteria remaining? Round your answer to the nearest whole number.
Mathematics
1 answer:
Papessa [141]3 years ago
4 0

Answer:

18 minutes

Step-by-step explanation:

A = A₀ (½)^(t / T)

where A is the final amount,

A₀ is the initial amount,

t is the time,

and T is the half life.

A = 140 when t = 10.  Solve for the half life:

140 = 700 (½)^(10 / T)

0.2 = ½^(10 / T)

log 0.2 = (10 / T) log 0.5

10 / T = 2.32

T = 4.31

When A = 40, t is:

40 = 700 (½)^(t / 4.31)

0.057 = ½^(t / 4.31)

log 0.057 = (t / 4.31) log 0.5

t / 4.31 = 4.13

t = 17.8

Rounded to the nearest whole number, it takes 18 minutes.

You might be interested in
Given the side measurements, classify the triangle as acute, obtuse, right, or not a triangle. 8, 12, 14
ratelena [41]

Answer:

not a triangle because 8,12,14 does not =180

Step-by-step explanation:

can i be brainliest

7 0
3 years ago
Patty walked 2/5 of a mile in 5 1/2 minutes. At this rate, how long will it take Patty to walk 3 miles?
lapo4ka [179]

Answer:

41.25 minutes i think sorry if its wrong

4 0
2 years ago
15 boys are needed to build a wall in 40 days how many boys are required to build the wall in 30 days​
bagirrra123 [75]

Step-by-step explanation:

40 days = 15 boys

1 day = 15/40 = 3/8

therefore,

30 days = 3/8 × 30

= 11.1/4 boys or 11.25boys

5 0
2 years ago
Can U Guys Please Answer These 3 Questions For Me
Damm [24]

Answer:

Step-by-step explanation:

7-2+(4•7)

5+28

=33

3 0
3 years ago
Read 2 more answers
Points (5, 3) and (6, 2) lie on line k. Which is the slope of the line that is parallel to k?
Over [174]
Slope of k=(3-2)/5-6
=-1
parallel lines have equal slopes
so slope of line parallel to k=-1
8 0
3 years ago
Other questions:
  • What is the value of <br> tan-1(100/41)
    14·1 answer
  • Hey can you please help me posted picture of question
    12·1 answer
  • 1-69.
    6·1 answer
  • Which equation shows how (–10, 8) can be used to write the equation of this line in point-slope form?
    9·1 answer
  • Janice bought 2 gifts yesterday. The price of one gift was 3 times the cost of the other. If both gifts cost $25.60 altogether,
    14·2 answers
  • I need help ASAP PLEASE!
    11·1 answer
  • How many of the 100 bin A items can be recycled at a specialized center?
    10·1 answer
  • The value of the intercept for the graph of 4x-5y=40 i s<br> A 10<br> B 4/5 <br> C-4/5 <br> D -8
    12·1 answer
  • I NEED HELP ASAP!!<br> like right now plz I will do anything
    10·1 answer
  • Mathematical
    11·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!