MooMooooMooM

Go to www.desmos.com and in the graphing thing put both x+y-20 and xy=40.

1728

First convert everything to base 10. \(242_5\) in base 10 is \(2*1+4*5+2*25, =72\) . \(367_8\) in base 10 is \(7*1+6*8+3*64=247\).

If the plumber works for 3.5 hours, multiply 3.5 by 72 to get 252. 252+ the base cost of 247=

499 dollars.

If the radius is 2 inches long, the area is 4pi square inches. Doubling the radius to 4, the area of that would be 16pi square inches. 16pi-4pi=

12pi square inches.'

$ 54.60

The shaded exterior wall is 6*8=48 square feet. One of the roof tops is 5*8=40 square feet, so both will be 80 square feet. 80+48=128. The sliding is 8*12=96 square feet, so we need two pieces. 2*$ 27.30=$ 54.60

If we want to replace, we want to make the amount of girls more than half of the class. SInce there are 40 kids, half the class would be 20, so the greatest number larger than half the class is 21. So we want at least 21 girls. 60% of 40 = .6*40=6*4=24. If there are 24 boys, then there are 16 girls. 21-16 is 5 girls have to be the replacements for 5 boys.

19+11+19+11=30+30=60

19:60

With the info, we try to sum the equation to something useful. We turn the lines into inequalities. Adding the first inequality to two times the second gets us
 

\(8x+13y=(2x+5y)+2(3x+4y)\geq 10+2\cdot 12 = \boxed{34} \)

credit to aops for the solution

30% of 60% is 18%

10% of 40% is 4%

18%+4%=22%

22/100

11/50