Answer:
40 14/25 years
Step-by-step explanation:
Well, this certainly is fun.
First, to find the fraction of the doctor's life which 13 years represents, subtract the fractions from 1 (and in this case l stands for lifetime):


So, multiply this equation by the reciprocal of 25/78 to isolate one of l:

years
Let's first break it down to the time 8 people need for one wall. That would be 10 minutes, right? If one person would have to do it in stead of 8, you'd expect him to take 80 minutes.
To paint 7 walls, he would nee 7x80 = 560 minutes. 10 people would do that 10 times faster, ie., 56 minutes.
I know puzzles like these always have a mindtrick. Did I miss anything?? ;-)
The area of room is 812 square feet, cost of carpet to cover the room is $6739.6 and the remaining square feet of carpet are covered by furniture is 203 square feet.
<h3>What is the area of trapezoid?</h3>
The area of the trapezoid is the space occupied by it on the two dimensional plane. The area of this figure is half of the product of height and sum of sides.

Here, (a and b) are the base sides of the trapezoid and (h) is the height.
A room is shaped like a trapezoid which has the height of 28 feet and the length of sides as 23 ft and 35 ft. Thus, the area of it is,

Carpet costs $8.30 per square foot. Thus, the cost of carpet with area 812 ft² is,
C=812×$8.30
C=$6739.6
Furniture covers 25% of the floor. Thus, the remaining square feet of carpet are covered by furniture is,

Thus, the area of room is 812 square feet, cost of carpet to cover the room is $6739.6 and the remaining square feet of carpet are covered by furniture is 203 square feet.
Learn more about the area of trapezoid here;
brainly.com/question/1410008
#SPJ1
Given:
Karen earns $54.60 for working 6 hours.
Amount she earns varies directly with the number of hours she works.
She need to work to earn an additional $260.
To find:
Number of hours she need to work to earn an additional $260.
Solution:
Let the amount of earnings be A and number of hours be t.
According to question,

...(i)
where, k is constant of proportionality.
Karen earns $54.60 for working 6 hours.

Divide both sides by 6.


Put k=9.1 in (i).

Substitute A=260 in the above equation.

Divide both sides by 9.1.



Therefore, she need to work extra about 29 hours to earn an additional $260.