<span>Find the wind speed and the plane's airspeed.
:
Let s = speed of the plane in still air
Let w = speed of the wind
then
(s-w) = plane speed against the wind
and
(s+w) = plane speed with the wind
:
Change 3 3/8 hrs to 3.375 hrs
:
The trips there and back are equal distance, (1890 mi) write two distance equations
dist = time * speed
:
3.375(s-w) = 1890
3.0(s + w) = 1890
:
It is convenient that we can simplify both these equations:
divide the 1st by 3.375
divide the 2nd by 3
resulting in two simple equations that can be used for elimination of w
s - w = 560
s + w = 630
----------------adding eliminates w, find s
2s = 1190
s =
s = 595 mph is the plane speed in still air
Find w
595 + w = 630
w = 630 - 595
w = 35 mph is the wind spee</span>
Answer:
D
Step-by-step explanation:
5 and 1/2 is not a whole nubmer in this list
Number 9 is 36 because there are 18/40 who feel safe, so it multiplied would be 36. C
Answer: The correct option is D, i.e.,30.
Explanation:
It the given equation we have two units l and dl.
Where l represents the liter and dl represents the deciliter. These are the volume units.
We know that,
1 liter = 10 deciliter
It means,
1 l = 10 dl
Multiply both sides by 3,
1\times 3 l = 10\times 3 dl
3 l = 30 dl
Therefore, the correct option is D and 3 l = 30 dl.
If each linear dimension is scaled by a factor of 10, then the area is scaled by a factor of 100. This is because 10^2 = 10*10 = 100. Consider a 3x3 square with area of 9. If we scaled the square by a linear factor of 10 then it's now a 30x30 square with area 900. The ratio of those two areas is 900/9 = 100. This example shows how the area is 100 times larger.
Going back to the problem at hand, we have the initial surface area of 16 square inches. The box is scaled up so that each dimension is 10 times larger, so the new surface area is 100 times what it used to be
New surface area = 100*(old surface area)
new surface area = 100*16
new surface area = 1600
Final Answer: 1600 square inches
