We know that
The exterior angle measures of a polygon must add up to 360°,
therefore
360°/72°=5 exterior angles
so
5 exterior angles, would mean 5 interior angles and therefore 5 sides to the polygon
The exterior angle and the interior angle of any polygon are supplementary and must add up to 180°.
exterior angle+interior angle=180°
interior angle=180°-exterior angle
interior angle=180°−72°-------> 108°
Each interior angle is 108°
The sum of the interior angles would be
5*108°=540°
the answer is
540°
Assume that the amount needed from the 5% solution is x and that the amount needed from the 65% solution is y.
We are given that, the final solution should be 42 ml, this means that:
x + y = 42 ...........> equation I
This can also be written as:
x = 42-y .......> equation II
We are also given that the final concentration should be 45%, this means that:
5% x + 65% y = 45% (x+y)
0.05x + 0.65y = 0.45(x+y)
We have x+y = 42 from equation I, therefore:
0.05x + 0.65y = 0.45(42)
0.05x + 0.65y = 18.9 .........> equation III
Substitute with equation II in equation III as follows:
0.05x + 0.65y = 18.9
0.05(42-y) + 0.65y = 18.9
2.1 - 0.05y + 0.65y = 18.9
0.6y = 18.9 - 2.1
0.6y = 16.8
y = 28 ml
Substitute with y in equation II to get x as follows:
x = 42-y
x = 42 - 28
x = 14 ml
Based on the above calculations:
amount of 5% solution = x = 14 ml
amount of 65% solution = y = 28 ml
The correct choice is:
The teacher will need 14 mL of the 5% solution and 28 mL of the 65% solution.
Answer:1,200 students
Step-by-step explanation:
540/45=12=1%
12*100=1,200
0.800 is already rounded to the nearest tenth
Brainliest for the person above me, thank you very much.
