Answer:
6kg pure copper and 30 kg 10% copper was mixed to give 36kg of 25% alloy
Step-by-step explanation:
Here, we want to produce 36 kg of 25% alloy
Let the Pure copper be x kg while 10% alloy be y kg
Pure copper is simply 100% copper
Thus;
x + y = 36 •••••(i)
Then;
100% of x + 10% of y = 25% of 36
= x + 0.1y = 9 •••••• ii)
From i x = 36-y
from ii, x = 9-0.1y
Equate both x
36-y = 9-0.1y
36-9 = 0.1y + y
0.9y = 27
y = 27/0.9
y = 30
x = 36-y
x = 36-30
x = 6 kg
The value of cos A is √(1 + x²)/ (1 - x²) /√1 + x
<h3>Trigonometric ratios</h3>
It is important to note that
sin A = opposite/ hypotenuse
cos A = adjacent/ hypotenuse
Then,
opposite = 
Hypotenuse = 
Let's find the adjacent side using the Pythagorean theroem



cos A = x/hypotenuse

cos A = √(1 + x²)/ (1 - x²) /√1 + x
Thus, the value of cos A is √(1 + x²)/ (1 - x²) /√1 + x
Learn more about trigonometric identities here:
brainly.com/question/7331447
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Answer:
Approximately 24–36 pounds
Step-by-step explanation:
Given:
Weight of standard American Eskimo dog has mean= 30 pounds
A standard deviation= 2 pounds
For 99.7% of the dogs according to normal distribution would lie between 3 standard deviations on either side of the mean.
i.e. lower bound= Mean- 3 (standard deviation)
= 30-3(2)
=30-6
=24
Upper bound = Mean +3 (standard deviation)
= 30+3(2)
=30+6
=36
Hence the range of weights : 24-36 pounds
correct answer Approximately 24–36 pounds!
Answer:
D) 1pi in^3
Step-by-step explanation:
Volume formula for cylinder is:
V=pi*r^2*h
V=pi*1*1
V=pi in^3