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3 years ago

11

While testing a new vaccine, a lab technician noticed that the number of bacteria reduced by half every minute. How long does it

take for 3,000 bacteria to reduce to 375?

1 answer:

ANTONII [103]3 years ago

7 0

As we know that
x=x0*[1/2]n
putting the values
375=3000*[1/2]n
375/3000=<span>[1/2]n
</span>1/8=<span>[1/2]n
simplify
[1/2]3=</span><span>[1/2]n
by cancelling them
so n=3
so it will take 3 minutes
hope it helps</span>

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What is the sum or difference?

dlinn [17]

1. Ans: Option (B) $-6x^4$

Explanation:
Given: $2x^4 - 8x^4$
Take the common out:
=> $x^4(2 - 8)$

Hence: => $[tex]-6x^4$ [/tex] (Option B)

2. Ans: Option (D) $-3y^5$

Explanation:
Given: $6y^5 - 9y^5$
Take the common term(s) out:
=> $y^5(6-9)$

Hence: => $-3y^5$ (Option D)

3. Ans: Option (B) $9x^2 - 12x + 6$ <span> quadratic trinomial

Explanation:
</span>Given: $6 - 12x + 13x^2 - 4x^2$

The standard form of polynomial function must have the highest powered value at the start, then the second highest and so on.

=> $13x^2 - 4x^2 - 12x + 6$
=> $9x^2 - 12x + 6$ (Option B)

4. Ans: Option (C) $7.3x^2 + 0.8x + 1.3$

Explanation:
In order to find the total number of C<span>ommon and Endler's guppies, you need to add both Common and Endler's guppies' polynomials, as follows:

</span>Common guppies: $3.1x^2 +6.0x + 0.3$ <span>
Endler's guppies: </span> $4.2x^2 - 5.2x + 1.0$
(add both)
-----------------------------------------------------------------
Total number: $7.3x^2 +0.8x + 1.3$
-----------------------------------------------------------------
Hence the ans is Option(C) $7.3x^2 + 0.8x + 1.3$

5. Ans: Option (D) $2x^2(133 - 18 \pi )$

Explanation:
First let's find the total area of the yard:
Total Area of the Yard = 14x * 19x = $266x^2$

Now the area of the circular fountain:
Area of the Circular Fountain = $\pi r^2$
Since, r=6x
Therefore,
Area of the Circular Fountain = $\pi (6x)^2 = 36 \pi x^2$

Now the final Area of the yard would be:
Final area of the Yard = Total Area of the Yard - Area of the Circular Fountain
Final area of the Yard = $266x^2$ - $36 \pi x^2$
=> Final area of the Yard = $2x^2(133 - 18 \pi)$ (Option D)

6. Ans: Option (A) $56x^2$

Explanation:
First let's find the total area of the lot:
Total Area of the lot= 6x * 10x = $60x^2$

Now the area of the stadium:
Area of the stadium = 1x * 4x = $4x^2$

Now the final Area of the lot would be:
Final area of the lot= Total Area of the lot - Area of the stadium
Final area of the lot= $60x^2$ - $4x^2$
=> Final area of the lot = $56x^2$ (Option A)

-i

4 0

3 years ago

Read 2 more answers

HELP ME I WILL MARK BRAINLIEST

Westkost [7]

Answer:

The answer is 1/15

I hope it helps

7 0

3 years ago

mash [69]

Answer:I dont know but i think it is 1/2

Step-by-step explanation:

hope this helps

6 0

2 years ago

skyalr makes turkey sandwiches for a family. he purchases 5 pounds 4 ounces of sliced Turkey for $26.88.what is the unit cost pe

algol [13]

Answer:

$0.32/ounce

Step-by-step explanation:

Total cost of Turkey - $26.88

Amount Purchased - 5 pounds 4 ounces

16 ounces in a pound

5 x 16 + 4 = 84

$\frac{84x}{84} = \frac{26.88}{84}$

x = $0.32

7 0

3 years ago

There are 130 people in a sport centre.

Mashcka [7]

Answer:

<h2>7/130</h2>

Step-by-step explanation:

Using set notation to answer the question. let:

n(U) be the total people in a sport centre =130

n(G) be number of people that use the gym. = 76

n(P) be number of people that use the swimming pool. = 60

n(T) be number of people that use the track = 32

n(G∩P) be number of people that uses the gym and the pool = 23

n(P∩T) be number of people that uses the pool and the track = 8

n(G∩T) be number of people that uses the gym and the track = 320

n(G∩P∩T) be number of people that uses all three facilities = 6

Using the relationship below;

n(U)= n(GUPUT)+n(GUPUT)'

where n(GUPUT)' is the number of people that doesn't use any facility.

Before we can get that, we need to know n(GUPUT) using the formula;

n(GUPUT) = n(G) + n(P)+n(T)-n(G∩P)-n(P∩T)-n(G∩T)+n(G∩P∩T)

n(GUPUT) = 76+60+32-23-8-20+6

n(GUPUT) = 123

n(GUPUT)' = n(U)- n(GUPUT)

n(GUPUT)' = 130 - 123

n(GUPUT)' = 7

This means that 7 person doesn't use any facility.

Probability that a person selected at random doesn't use any facility = n(GUPUT)' /n(U) = 7/130

3 0

3 years ago