HELP WITH 20 PLEASE!

Out of a salary of $4500. I kept 1/3 as saving. Out of the remaining money. I spend 50% on food and 20% on house rent. How much

Step2247 [10]

Well 1/3 for savings means that you save 1/3*4500 or 1500 dollars.
You then have $3000 left. Of this if you spend 50% on food, you spend 0.5*3000 or 1500 dollars on food.

7 0

3 years ago

Convert the length 7 centimeters to meters. Compare the numerical values when both numbers are written in scientific notation

miv72 [106K]

<span>1. </span><span>Given numbers
=> 7 centimeters convert to meters
In every 1 meter there are 100 centimeters
=> 7 / 100
=> 0.07
Therefore in 7 centimeters there are 0.07 meters.
7 cm is a whole number while 0.07 m is a decimal number
Scientific Notation of each numbers
=> 7 cm = 7 x 10^0
=> 7 m = 1 x 10^-2
Scientific notation by the way is an expression used by the scientist to make a large number or very small number easy to handle.

</span>

4 0

3 years ago

Sphere and a cylinder have the same radius and height. The volume of the cylinder is 64 meters cubed.

Mrrafil [7]

Answer:

C. 128/3 meters cubed

Step-by-step explanation:

The volume of a cylinder is denoted by: $V=\pi r^2h$ , where r is the radius and h is the height. We know it's equal to 64, so we can set that equal to V:

$V=\pi r^2h$

$64=\pi r^2h$

We know that the sphere and cylinder have the same height and radius. However, the "height" of a sphere is actually the same as its diameter, which is twice its radius. Then, we can replace h in the above equation with 2r:

$64=\pi r^2h$

$64=\pi r^2*2r=2\pi r^3$

$\pi r^3=64/2=32$

Now, the volume of a sphere is denoted by: $V=\frac{4}{3} \pi r^3$ , where r is the radius. From above, we know that $\pi r^3=32$ , so we can plug this into the equation:

$V=\frac{4}{3} \pi r^3$

$V=\frac{4}{3} *32=128/3$

Thus, the answer is C.

4 0

3 years ago

Read 2 more answers

Two airplanes are flying in the air at the same height. Airplane A is flying east at 300mi/h and airplane B is flying north at 2

Ipatiy [6.2K]

Answer:

$\frac{dAB}{dt}=340 mil/h$

Step-by-step explanation:

The change of distance over time of the plain A is 300 mi/hour and 200 mi/hour for plane B. O is the point of the airport.

So, the distance from A to O AO = 90 miles and BO = 120 miles.

Now, we have a right triangle here. We can use the Pythagorean theorem, so the distance between the planes will be:

$AB^{2} =AO^{2}+BO^{2}$ (1)

$AB =\sqrt{AO^{2}+BO^{2}}=$

$AB =\sqrt{90^{2}+120^{2}}=150 miles$

If we take the derivative of the equation (1) we could find the change of the distance between planes.

$2AB\frac{dAB}{dt}=2AO\frac{dAO}{dt}+2BO\frac{dBO}{dt}$

$2*150\frac{dAB}{dt}=2*90*300+2*120*200=102000 mil/h$

$\frac{dAB}{dt}=\frac{102000}{150*2}$

Finally,

$\frac{dAB}{dt}=340 mil/h$

I hope it helps you!

6 0

3 years ago

What is the value of x? Thanks for the help

-BARSIC- [3]

Hello! I can help you! First things first, because they are both the same angles on opposite sides, let's set this up in the form of an equation and solve for "x". It would be set up like this:

2x + 20 = 3x - 30

You see up top that it says 2(x + 10). What you would do is multiply what's in the parenthesis by 2, in order to get 2x + 20. Then put the equal sign and write 3x - 30. Subtract 3x from both sides to get -1x + 20 = -30. Subtract 20 from both sides to get -1x = -50. Divide each side by -1 to isolate the "x". In this case, because you are dividing a negative number by a negative number, your quotient will be positive. -50/-1 is 50. Let's plug in the value as "x" and see if it works. 50 * 2 is 100. 100 + 20 is 120. 50 * 3 is 150. 150 - 30 is 120. 120 = 120. There. x = 50.

8 0

3 years ago