Answer:
C. 2.0 < t < 2.5
Step-by-step explanation:
time = distance / speed
The circumference of the lake is given by ...
C = πd = 2π miles ≈ 6.28 miles
Then Johanna's time is ...
(6.28 mi)/(3 mi/h) ≈ 2.09 h
This time is in the interval (2, 2.5), so matches choice C.
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<em>Alternate solution</em>
If we take pi to be 3, then this boils down to ...
2×3/3 = 2 . . . hours
Pi is on the order of 5% more than 3, so her time will be on the order of 5% more than 2 hours, or just above 2, but not as great as 2.5 hours. This sort of estimating can get you to the correct answer without a calculator.
Answer:
68.1 units²
Step-by-step explanation:
Start by finding the area of the rectangle...
Then, find the area of the semicircle...
Now, add the two to get...
54+14.1=68.1
Answer:
What is the mission
Step-by-step explanation:
Answer:
40 and 10
Step-by-step explanation:
1. if the length is 'l' and height is 'h', then according to the condition 1/4*l=h.
2. if the given area is 400, it means, h*l=400;
3. if to substitute h=1/4*l into the formula of the area, then
l*l*1/4=400; ⇔ 1/4*l²=400;
4. if to calculate the value of the 'l', then l=40 (the required length).
5. if to substitute l=40 into 1/4*l=h, then h=10 (the required height).
