Set up two equations:
1st: P (for Price family) + J (for Jenkins family) = 45 hours
2nd: 20P + 35J = 1200 liters
Rewrite the first equation as P = 45 – J
Replace P in the second equation:
20(45-J) + 35J = 1200
Simplify:
900 -20J + 35J = 1200
900 +15J = 1200
Subtract 900 from both sides:
15J = 300
Divide both sides by 15:
J = 300/15
J = 20
Jenkins used theirs for 20 hours
Price used theirs for 45-20 = 25 hours.
Answer:
All residents of the community
Step-by-step explanation:
Not sure if this is fully correct but the 2nd and 3rd option is wrong (Edg 2021)
-- The smallest perimeter you can make with a certain area
is a circle.
-- The NEXT smallest perimeter with the same area is a square.
With 1-ft by 1-ft square bricks, the shortest perimeter she could
make would be by using her bricks to make it as square as possible.
Without cutting bricks into pieces, the best she could do would be
(13 bricks) x (3 bricks) .
= (13-ft) x (3-ft)
Perimeter = (2 x length) + (2 x width)
= (2 x 13-ft) + (2 x 3-ft)
= (26-ft) + (6-ft) = 32 feet <== shortest perimeter.
-- Then, the more UNSQUARE you make it, the more perimeter
it takes to enclose the same area. That means Mary has to make
a rectangle as long and skinny as she can.
The longest perimeter she can make (without cutting bricks into
pieces) is (39 bricks) x (1 brick) .
= (39-ft) x (1-ft) .
Perimeter = (2 x length) + (2 x width)
= (2 x 39-ft) + (2 x 1-ft)
= (78-ft) + (2-ft) = 80 feet .
What she'll have then is a brick path, 39 feet long and 1 foot wide,
and when you walk on it, you'll need to try hard to avoid falling off
because it's only 1 foot wide.
