Answer: 3 miles per hour
<u>Step-by-step explanation:</u>
Use the formula "distance (d) = rate (r) x time (t)" to create a system of equations.
Let "r" represent the rate they are rowing
Let "c" represent the current
time rate distance <u>EQUATION</u>
Downstream: 4 hours r + c 40 miles 4(r + c) = 40
Upstream: 10 hours r - c 40 miles 10(r - c) = 40
Distribute, then eliminate r to solve for c:
Down: 4r + 4c = 40 → 5(4r + 4c = 40) → 20r + 20c = 200
Up: 10r - 10c = 40 → -2(10r - 10c = 40) → <u>-20r + 20c</u> =<u> -80</u>
40c = 120
<u> ÷40 </u> <u>÷40 </u>
c = 3
Answer:
20n
Step-by-step explanation:
Multiply square feet per person times the number of persons to find square feet.
The units analysis looks like this:
4 = 2*2
6 = 2*3
9 = 3*3
LCD = 2 * 3* 2 * 3 = 36
so the fractions are 3/4 * 9/9 = 27/36
5/6 = 30/36 and 5/9 = 20/36
We know that
volume of a sphere=(4/3)*pi*r³----> (r/3)*(4*pi*r²)
and
surface area of sphere=4*pi*r²
so
the volume of a sphere=(r/3)*surface area of sphere
therefore
if r=3
volume of a sphere=(3/3)*surface area of sphere
volume of a sphere=surface area of sphere
if r> 3
the term (r/3) is > 0
so
volume of a sphere > surface area of sphere
if r<3
the term (r/3) is < 0
so
volume of a sphere < surface area of sphere
examples
1) for radius r=3 units
volume of a sphere=(4/3)*pi*3³----> 113.04 unit³
surface area=4*pi*3²----> 113.04 units²
volume is equal to surface area
2) for radius r=10 units
volume of a sphere=(4/3)*pi*10³----> 4186.67 unit³
surface area=4*pi*10²----> 1256 units²
volume is > surface area
3) for radius r=2 units
volume of a sphere=(4/3)*pi*2³----> 33.49 unit³
surface area=4*pi*2²----> 50.24 units²
volume is < surface area
107 m
Step-by-step explanation:
Step 1:
Here the microscope magnifies by 10 times.
The initial length is 10.7 m
Step 2:
Let the object be magnified by 10 times . Then, 10 × 10.7 = 107
