Answer:
45, 36
Step-by-step explanation:
let x y minutes be the time for pipes to fill the tank, let n be the water needed to fill the tank.
x-y=9
(n/x)*20+(n/y)*20=n
n is removed by dividing the 2nd equation by n
here u get:
(1/x+1/y)*20=1
you sub x=9+y into the above equation
1/y+1/(9+y)=1/20
((9+y)+(y))*20=(9+y)(y)
180+40y=9y+y2
y2-31y-180=0
then use the quadratic formula and u will find y=36 or -5
-5 is rejected because it is negative
x=36+9=45
therefore it is 36 mins and 45 mins
Answer:
The answer is explained below
Step-by-step explanation:
Given that:
mean (μ) = 7 and standard deviation (σ) = 1.5.
The z score is used in statistic used to measure the number of standard deviation by which the raw score is above or below the mean value. It is given by:
To find the Probability that x < 8.8, we first find the z score using:
From the z tables, P(x < 8.8) = P(z < 1.2) = 0.8849 = 88.49%
Answer:
False
Step-by-step explanation:
an inequality is a relation which makes a non-equal comparison between two numbers or other mathematical expressions.
D. Aidan’s
The larger the sample size (number of people asked), the more accurate the results generally are, due to the law of large numbers.
So x + y = 45, and 4x + 5y = 195. Get y by itself. Subtract x from both sides in the first equation to get y = 45 -x, and subtract 4x from the second equation to get 5y = 195 - 4x. Divide by 5 to both sides to get y = 39 - 4/5x. 39 - 4/5x = 45 - x. Add x to both sides to get 39 - 1/5x = 45. Subtract 39 from both sides to get -1/5x = 6. Divide by -1/5 to get x = -30, or 30. In the first equation, do 30 + y = 45. Subtract 30 from both sides to get y = 15. Check. 4(30) + 15(5) = 195, or 120 + 75 = 195.
