Answer:
John should use:
4 grams of the 30% solution and 16 grams of the 60% solution
Step-by-step explanation:
Let the number of grams of the 30% solution = x
Let the number of grams of the 60% solution = y
John needs 20 grams of 54% acid solution for his science project.
Hence,
x + y = 20 grams..... Equation 1
x = 20 - y
His school's science lab has bottles of 30% solution and bottles of 60% solution.
30% × x + 60% × y = 54% × 20
0.3x + 0.6y = 10.8......Equation 2
We substitute 20 - y for x in Equation 2
0.3(20 - y) + 0.6y = 10.8
6 - 0.3y + 0.6y = 10.8
- 0.3y + 0.6y = 10.8 - 6
0.3y = 4.8
y = 4.8/3
y = 16 grams
x = 20 - y
x = 20 - 16
x = 4 grams
Therefore, John should use:
4 grams of the 30% solution and 16 grams of the 60% solution
Answer:
285, 629, 7392, 15708,43695
Step-by-step explanation:
If you add the digits of the number together, it should be divisible by 9. If it isn't, then it must be a multiple of only 3, not 9.
Firstly you multiply 5 with everything in the brackets on the left side of = . and than you put t on the left side and change sign (if it was + then its going to be -) and numbers on right side and do the same with signs. then just calculate the rest
5(5t +1) = 25t - 7
25t + 5 = 25t - 7
25t - 25t = -7 + 5
0=-2
the statement is false
Answer:
<em>795.596≤u≤804.403</em>
Step-by-step explanation:
Confidence interval is expressed using the formula;
CI = xbar ± (z*s/√n)
xbar is the sample mean
z is the z score at 98% confidence
s is the standard deviation
n is the sample size
Given
xbar = 800
z = 2.33
s = 10
n = 28
Substitute into the formula;
CI =800 ± (2.33*10/√28)
CI = 800 ± (2.33*10/5.2915)
Ci = 800± (2.33* 1.8898)
CI = 800 ± 4.4033
CI = (800-4.4033, 800 + 4.4033)
CI = (795.596, 804.403)
<em>Hence an interval estimate of u with 98% confidence is expressed as </em>
<em>795.596≤u≤804.403</em>
Answer:
if you take 180-124 you would get 56 then you would take 56 divided by 2x which would give you 28
Step-by-step explanation:
