All categories

2 years ago

What percent of 40 is 20?

Mathematics

2 answers:

VikaD [51]2 years ago

7 0

Answer:

200%

Step-by-step explanation:

20 = 100% (in this case)

40 = 200% (because you multiply both sides to get 40)

Therefore, 40 is 200% of 20.

7nadin3 [17]2 years ago

3 0

Answer:

Step-by-step explanation:

When doing these types of problems, we convert the percent to a decimal. In this case,

40%=0.4

0.4*20=8

You might be interested in

Given Δ ABD ≅ ΔEBD, what can you conclude?

Anna71 [15]

You can conclude that AE = DE because the triangles are about equal

8 0

2 years ago

Read 2 more answers

Target pays $13 per pair of sunglasses and uses 30% markup rate. What is targets selling price for the sunglasses?

Elena L [17]

Answer:

$16.90

Step-by-step explanation:

First you need to find how much the markup is in dollars.

Multiply 13(0.3).

This will give you 3.9.

Then you add this to the original cost of the glasses.

13+3.9= 16.9.

So, the final cost of the glasses is $16.90.

3 0

3 years ago

Element X is a radioactive isotope such that its mass decreases by 26% every day. If an experiment starts out with 810 grams of

ioda

Answer:

The hourly decay rate is of 1.25%, so the hourly rate of change is of -1.25%.

The function to represent the mass of the sample after t days is $A(t) = 810(0.74)^t$

Step-by-step explanation:

Exponential equation of decay:

The exponential equation for the amount of a substance is given by:

$A(t) = A(0)(1-r)^t$

In which A(0) is the initial amount and r is the decay rate, as a decimal.

Hourly rate of change:

Decreases 26% by day. A day has 24 hours. This means that $A(24) = (1-0.26)A(0) = 0.74A(0)$ ; We use this to find r.

$A(t) = A(0)(1-r)^t$

$0.74A(0) = A(0)(1-r)^{24}$

$(1-r)^{24} = 0.74$

$\sqrt[24]{(1-r)^{24}} = \sqrt[24]{0.74}$

$1 - r = (0.74)^{\frac{1}{24}}$

$1 - r = 0.9875$

$r = 1 - 0.9875 = 0.0125$

The hourly decay rate is of 1.25%, so the hourly rate of change is of -1.25%.

Starts out with 810 grams of Element X

This means that $A(0) = 810$

Element X is a radioactive isotope such that its mass decreases by 26% every day.

This means that we use, for this equation, r = 0.26.

The equation is:

$A(t) = A(0)(1-r)^t$

$A(t) = 810(1 - 0.26)^t$

$A(t) = 810(0.74)^t$

The function to represent the mass of the sample after t days is $A(t) = 810(0.74)^t$

5 0

2 years ago

Of all the rectangles with a perimeter of 168 feet, find the dimension of the one with the largest area

dolphi86 [110]

<span>The rectangle with the largest area with a given perimeter will be a square - so the sides will be equal. So we need to find length of side, L, such that 4*L=168. L = 168/4 L=42. So the dimensions of the rectangle that maximizes the area with a perimiter of 168 feet are: 42 feet by 24 feet.</span>

3 0

3 years ago

I need help with this someone!!

Alex

Answer:

Do u have answer choices?

4 0

3 years ago

Read 2 more answers