Answer:
Let b = rate of the boat.
Let r = rate of the river.
The rate going downstream is b + r.
The rate going upstream is b - r.
rate x time = distance
4(b + r) = 144 ---> b + r = 36 [divide both sides by 4]
9(b - r) = 144 ---> b - r = 16 [divide both sides by 9]
Add town: 2b = 52
Divide by : b = 26 mi/hr
r = 10 mi/hr
Step-by-step explanation:
Answer:
Hi, there your answer will C. 85pi ft^2
Step-by-step explanation:
pi(5)(12)+pi(5)^2
60pi+25pi
85pi ft^2
Hope this helps :)
Here's a pattern to consider:
1+100=101
2+99=101
3+98=101
4+97=101
5+96=101
.....
This question relates to the discovery of Gauss, a mathematician. He found out that if you split 100 from 1-50 and 51-100, you could add them from each end to get a sum of 101. As there are 50 sets of addition, then the total is 50×101=5050
So, the sum of the first 100 positive integers is 5050.
Quick note
We can use a formula to find out the sum of an arithmetic series:

Where s is the sum of the series and n is the number of terms in the series. It works for the above problem.
Here is the answer with an explanation!