Roberto overtakes Juanita at the rate of (7.7 mi)/(11 h) = 0.7 mi/h. This is the difference in their speeds. The sum of their speeds is (7.7 mi)/1 h) = 7.7 mi/h.
Roberto walks at the rate (7.7 + 0.7)/2 = 4.2 mi/h.
Juanita walks at the rate 4.2 - 0.7 = 3.5 mi/h.
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In a "sum and diference" problem, one solution is half the total of the sum and difference. If we let R and J be the respective speeds of Roberto and Juanita, we have
R + J = total speed
R - J = difference speed
Adding these two equations, we have
2R = (total speed + difference speed)
R = (total speed + difference speed)2 . . . . . as computed above
ALL of their points are common. If you multiply each side of the first equation by 2, you'll see that they're both the same line.
Answer:
the closest answer is the last option, so I would say that is the correct one.
Step-by-step explanation:
4.5 x 4.5 x π =
20.25 x π =
63.6172....
1) $23
2) %45
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Answer:
1, 3, and 4
Step-by-step explanation:
