Answer:
Speed of boat in still water = 11 miles per hour.
Step-by-step explanation:
Speed = distance / time
or
Distance= Speed * time
Let s be speed of the boat upstream and r be the speed of the river.
Then
Upstream speed= s- r = 60/6= 10 miles per hour
Downstream speed= s+r= 72/6= 12 miles per hour
Therefore
s-r= 10--------- equation A
s+r= 12--------- equation B
Adding equation A and Eq. b
s-r= 10--------- equation A
<u>s+r= 12--------- equation B </u>
<u>2s = 22 </u>
<u />
or
s= 22/2= 11 miles per hour.
Speed of boat in still water = 11 miles per hour.
Step-by-step explanation:
hope this helps you to understand
Answer:
1 dollar
Step-by-step explanation:
If he charges 15 dollars an hour for a canoe, that means that if she rents for 0.15 hours she pays 1 dollar. Hope this helps :)
Answer:
THE ANSWER IS 222
Step-by-step explanation:
The sum of the first 20 terms of an arithmetic sequence with the 18th term of 8.1 and a common difference of 0.25 is 124.5
Given,
18th term of an arithmetic sequence = 8.1
Common difference = d = 0.25.
<h3>What is an arithmetic sequence?</h3>
The sequence in which the difference between the consecutive term is constant.
The nth term is denoted by:
a_n = a + ( n - 1 ) d
The sum of an arithmetic sequence:
S_n = n/2 [ 2a + ( n - 1 ) d ]
Find the 18th term of the sequence.
18th term = 8.1
d = 0.25
8.1 = a + ( 18 - 1 ) 0.25
8.1 = a + 17 x 0.25
8.1 = a + 4.25
a = 8.1 - 4.25
a = 3.85
Find the sum of 20 terms.
S_20 = 20 / 2 [ 2 x 3.85 + ( 20 - 1 ) 0.25 ]
= 10 [ 7.7 + 19 x 0.25 ]
= 10 [ 7.7 + 4.75 ]
= 10 x 12.45
= 124.5
Thus the sum of the first 20 terms of an arithmetic sequence with the 18th term of 8.1 and a common difference of 0.25 is 124.5
Learn more about arithmetic sequence here:
brainly.com/question/25749583
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