Answer: 490 grams of the first alloy should be used.
30 grams of the second alloy should be used.
Step-by-step explanation:
Let x represent the weight of the first alloy in grams that should be used.
Let y represent the weight of the second alloy in grams that should be used.
A chemist has two alloys, one of which is 15% gold and 20% lead. This means that the amount of gold and lead in the first alloy is
0.15x and 0.2x
The second alloy contains 30% gold and 50% lead. This means that the amount of gold and lead in the second alloy is
0.3y and 0.5y
If the alloy to be made contains 82.5 g of gold, it means that
0.15x + 0.3y = 82.5 - - - - - - - - - - - -1
The second alloy would also contain 113 g of lead. This means that
0.2x + 0.5y = 113 - - - - - - - - - - - - -2
Multiplying equation 1 by 0.2 and equation 2 by 0.15, it becomes
0.03x + 0.06y = 16.5
0.03x + 0.075y = 16.95
Subtracting, it becomes
- 0.015y = - 0.45
y = - 0.45/- 0.015
y = 30
Substituting y = 30 into equation 1, it becomes
0.15x + 0.3 × 30 = 82.5
0.15x + 9 = 82.5
0.15x = 82.5 - 9 = 73.5
x = 73.5/0.15
x = 490
Answer:
Sample size n = 1382
so correct option is D) 1382
Step-by-step explanation:
given data
confidence level = 99 %
margin of error = 3%
probability = 25 %
to find out
How large a sample size needed
solution
we know here P = 25 %
so 1 - P = 1 - 0.25
1 - P = 0.75
and we know E margin of error is 0.03 so value of Z for 99%
α = 1 - 99% = 1 - 0.99
α = 0.01
and
= 
= 0.005
so Z is here
= 2.576
so
sample size will be
Sample size n = 
put here value
Sample size n = (\frac{2.576}{0.03})^2 * 0.25 * 0.75
Sample size n = 1382
so correct option is D) 1382
The period is 2.
Normally the period of sin(x) is 2pi, but the pi inside the sin(pix) is a horizontal compression by a factor of 1/pi. So 2pi·1/pi = 2
The "1/2" and "+3" do not impact the period. Those just impact the amplitude (vertical aspect) of the graph.
Answer:
i can see the image
Step-by-step explanation:
brainliest me