First term: a1 = 151
common difference: d = -14 (we decrease by 14 each time, eg, 151-14 = 137)
nth term of this arithmetic sequence is...
an = a1+d(n-1)
an = 151+(-14)(n-1)
an = 151-14n+14
an = -14n+165
This will be used in the formula below
Sn = n*(a1+an)/2
<span>Sn = n*(151+(-14n+165))/2
</span><span>S26 = 26*(151+(-14*26+165))/2 ... replace every n with 26
</span>S26 = -624
The final answer here is choice C) -624
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Answer: 15
Step-by-step explanation:
x = one point shots
y = two point shots
1) Setup your equations.
x + y = 52
x + 2y = 89
2) Isolate a variable.
x = 52-y
3) Plug in.
(52-y) + 2y = 89
52 +y =89
y=37
4) Solve for x.
x = 52 -37
x=15
5) Check your answer.
15 + 2(37) = 89
15+74=89
89=89
37+15 = 52
52=52
x = one point shots
y = two point shots
1) Setup your equations.
x + y = 52
x + 2y = 89
2) Isolate a variable.
x = 52-y
3) Plug in.
(52-y) + 2y = 89
52 +y =89
y=37
4) Solve for x.
x = 52 -37
x=15
5) Check your answer.
15 + 2(37) = 89
15+74=89
89=89
37+15 = 52
52=52
Answer:
2 hours
Step-by-step explanation:
Let x mph be the speed of motorboat in still water and y mph be the speed of current.
A raft and a motorboat simultaneously leave from the same point and move down the river, then speeds down the river are:
motorboat = x + y mph
raft = y mph
In two hours they will cover:
motorboat = 2(x+y) miles
raft = 2y miles
After 2 hours the motorboat turns around and starts moving towards the raft (against the current), so its speed is now x - y mph.
Let t be the time they move towards each other. In t hours, they cover
motorboat = t(x - y) miles
raft = ty miles
The distance from the starting point to the turning point is the same as the sum of the distances the raft covers and the motorboat covers after turning around, so
Calculate the mean, median, and mode of the following set of data. Round to the nearest tenth. 3, 15, 3, 3, 1, 11, 2, 8, 3, 7, 1
zubka84 [21]
The mode is 3. The median is 3. The mean is 6.45 and rounded to the nearest tenth is 6.5. So the mean is 6.5.
