Let's say the test is 100 points.
The 70% mean means that the mean for the 30 students was 70 points. That means 2100 points were scored between all 30 students. (70·30=2100)
20 boys had a mean of 62% or 62 points for our test. That means the boys earned 62·20 points, or 1240 points.
That then means the girls earned 2100 - 1240 points, or 860 points.
Since there are 10 girls, 860/10 = 86 or 86% mean on the test.
Girls rock!
Answer:
C
Step-by-step explanation:
Answer:
x = 35
Step-by-step explanation:
Solve for x:
5 (x + 20) = 7 x + 30
Expand out terms of the left hand side:
5 x + 100 = 7 x + 30
Subtract 7 x from both sides:
(5 x - 7 x) + 100 = (7 x - 7 x) + 30
5 x - 7 x = -2 x:
-2 x + 100 = (7 x - 7 x) + 30
7 x - 7 x = 0:
100 - 2 x = 30
Subtract 100 from both sides:
(100 - 100) - 2 x = 30 - 100
100 - 100 = 0:
-2 x = 30 - 100
30 - 100 = -70:
-2 x = -70
Divide both sides of -2 x = -70 by -2:
(-2 x)/(-2) = (-70)/(-2)
(-2)/(-2) = 1:
x = (-70)/(-2)
The gcd of -70 and -2 is -2, so (-70)/(-2) = (-2×35)/(-2×1) = (-2)/(-2)×35 = 35:
Answer: x = 35
The total cost including taxes is $156
Answer: B. 25.2 units
Step-by-step explanation:
The kite consists of 4 right angle triangles. The two smaller right angles are equal. Also, the two bigger right angles are equal.
To determine the hypotenuse of each triangle, we would apply Pythagoras theorem which is expressed as
Hypotenuse² = opposite side² + adjacent side²
Considering the smaller triangle,
Hypotenuse² = 4² + 3² = 16 + 9 = 25
Hypotenuse = √25 = 5
Considering the smaller triangle,
Hypotenuse² = 7² + 3² = 49 + 9 = 58
Hypotenuse = √58 = 7.616
The perimeter of the kite is the sum of the length of each side. Therefore,
Perimeter = 5 + 5 + 7.616 + 7.616 = 25.2 units to the nearest tenth
