Answer:
The answer is 40 and I calculated it, it’s true
Step-by-step explanation:
I promise
Since Irina can paint 1 room in 9 hours, that means she paints 1/9 of the room in 1 hour. Her portion of the equation would be 1/9x, with x being the number of hours she works and 1/9 of a room per hour being her speed.
Since Paulo can paint 1 room in 8 hours, that means he paints 1/8 of the room in 1 hour. His portion of the equation would be 1/8x, with x being the number of hours he works and 1/8 of a room per hour being his speed.
The equation would then be 1/9x + 1/8x = 1 (Irina's portion of the room, plus Paulo's portion of the room, equal to one whole room).
Find a common denominator. 72 is the first number that both 9 and 8 divide evenly into. Since 9*8 = 72, we multiply the top of 1/9 by 8 to convert the fraction and get 8/72x. Since 8*9 = 72, we multiply the top of 1/8 by 9 to convert the fractio and get 9/72x. We now have 8/72x+9/72x=1
17/72x=1
Divide both sides by 17/72:
17/72x ÷ 17/72 = 1÷17/72
x=1/1 ÷ 17/72
x=1/1 * 72/17
x=72/17=4.24
Together it should take them 4.24 hours.
Answer:
B.Dining out
Step-by-step explanation:
<u>I hope the below question is the full one that you want to ask</u>
<em>Select the correct answer. Zara is six months into her first job, and she’s also attending community college. She is planning to start saving a portion of her paycheck and has created a monthly budget to track her spending. Which budget item should Zara reduce to increase her savings? A. college tuition B. dining out C. rent D. utility bills</em>
<em />
I think it is B: dinning out.
Because A C D are fixed cost, she could not adjust or change by herself. She can only save money when she cooks, do not need to go out for food.
Answer:
Step-by-step explanation:
Let M be the heights of men in the United States and W be the heights of women in the United States
Given that M is N(69.1, 2.9) and W (63.7, 2.7)
For a husband and wife we have average height as
=Z (say)
![Mean =E(z) = \frac{1}{2} [E(M)+E(W)] = 66.4 inches](https://tex.z-dn.net/?f=Mean%20%3DE%28z%29%20%3D%20%5Cfrac%7B1%7D%7B2%7D%20%5BE%28M%29%2BE%28W%29%5D%20%3D%2066.4%20inches)
Var (Z) =![Var (\frac{x+y}{2} )=\frac{1}{4}[Var(x)+ Var(y)+2 cov (x,y)]\\](https://tex.z-dn.net/?f=Var%20%28%5Cfrac%7Bx%2By%7D%7B2%7D%20%29%3D%5Cfrac%7B1%7D%7B4%7D%5BVar%28x%29%2B%20Var%28y%29%2B2%20cov%20%28x%2Cy%29%5D%5C%5C)
=![0.25[2.9^2+2.7^2+2*r*sx*sy]\\= 0.25(20.398)\\=5.0995](https://tex.z-dn.net/?f=0.25%5B2.9%5E2%2B2.7%5E2%2B2%2Ar%2Asx%2Asy%5D%5C%5C%3D%200.25%2820.398%29%5C%5C%3D5.0995)
Mean = 66.4" and std dev = 2.258
