X = amount of 50% solution
y = total amount after mixing
Note that the amount of alcohol in the 20% solution is 80 (0.2) = 16 oz.
We have 2 unknowns, so we need 2 equations:
first, we can write the equation for the total volume:
y = x + 80
next, apply the percentages to get an equation for the amount of alcohol:
0.4 y = 0.5 x + 16
Finally, solve the pair of equations (in this case, by substitution of the 1st into the second:
0.4 (x + 80) = 0.5x + 16
0.4 x + 32 = 0.5X + 16
rearrange and combine like terms:
0.1x = 16
x = 160
from the 1st equation:
y = 160 + 80 = 240
Answer:
The standard error of the mean = 5.14 mins
Step-by-step explanation:
Number of random sample (n) = 20
Mean(X) = 31.25 mins
Standard deviation (α) = 23.7 mins
Standard error of mean =
standard deviation / √sample size
= 23.7/√20
= 23.7/4.4721
= 5.14 mins
Answer: 11
Step-by-step explanation: 
Answer:
1⅗
Step-by-step explanation:
=44/5÷11/2
when two fractions are dividing,turn the division sign into multiplication sign and take the reciprocal of one fraction.That is,in one fraction let the numerator become the denominator and the denominator become the numerator
=44/5×2/11
then 11 goes into forty-four. 4
therefore
=4/5×2/1
=8/5
=1⅗
He works 40 hrs....at 2.50 per hr...thats (40 * 2.50) = 100 bucks salary
he earned $ 250 in tips..
salary + tips = total income
100 + 250 = t
350 = t...so his total income add up to $ 350 <==
