The 80 eighth graders took a trip to Washington DC. The boys numbered 16 fewer than twice the number of girls. How many of the e
1 answer:
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<h3>Answer: 4368 square feet</h3>
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Explanation:
Check out the diagram below
I drew a rectangle with dimensions 56 ft by 78 ft.
Then I broke up the 56 into 50+6, and I broke up the 78 into 70+8
The reason for this is because it's fairly easy to multiply the areas of each smaller rectangle at this point
- In the upper left corner, we have an area of 50*70 = 3500. Note how this is basically 5*7 = 35, but we tack on the two zeros (from 50 and 70 combined)
- In the upper right corner, we have an area of 70*6 = 420
- In the lower left corner, we have an area of 50*8 = 400
- In the lower right corner, we have an area of 6*8 = 48
Add up all the areas found: 3500+420+400+48 = 4368
As a way to check, using your calculator shows that 56*78 = 4368
Answer:
4 mph
Step-by-step explanation:
The average speed of an object is given by the total distance covered by the time taken:
where
d is the total distance covered
t is the time taken
in the first part, the person runs for 0.4 hours at a speed of 7 mph, so the distance covered in the 1st part is
Then the distance covered in the second part is , so the total distance is
(1)
The total time elapsed is 0.4 hours (first part) + 0.8 hours (second part), so
So we can write the average speed as
(1)
We want the average speed to be 5 mph,
v = 5 mph
Therefore we can rearrange eq.(1) to find d2:
And therefore, the speed in the second part must be