Question 783473: 99, 98, 94, 85, 69 what is the next number in this series
Found 3 solutions by fcabanski, Cromlix, solver91311:
Answer by fcabanski(1391)   (Show Source):
You can put this solution on YOUR website! Check the differences between the numbers.
1,4,9,16. Check the differences between the differences (second difference).
3,5,7...there's the pattern: 3,5,7,9,11,13,15...
The next second difference is 9, thus the next difference is 16+9=25. 69-25=44.
99,98,94,85,69,44...
Answer by Cromlix(4381)  (Show Source):
You can put this solution on YOUR website! 99 -> 98 decrease of 1^2
98 -> 94 decrease of 2^2
94 -> 85 decrease of 3^2
85 -> 69 decrease of 4^2
69 -> 44 decrease of 5^2
Therefore next number = 44.
Hope this helps.
:-)
Answer by solver91311(24713)  (Show Source):
You can put this solution on YOUR website!
First thing to do is recognize that this is not a series. It is a sequence.
 is a series.
99 98 94 85 69 Starting with the 2nd term. Subtract each term from
1 4 9 16 the term immediately to its left.
-3 -5 -7 Repeat
2 2 Stop here because the results of two adjacent subtractions were equal
Since the last row shows equal results, a 3rd element in that last row would have also been 2, so write that in
99 98 94 85 69
1 4 9 16
-3 -5 -7
2 2 2
That 2 would have been the result of a previous subtraction, so put in a -9 i the row above
99 98 94 85 69
1 4 9 16
-3 -5 -7 -9
2 2 2
Then a 25 in the row above that, and finally put in the 44 (69 - 25) which is the desired next term.
99 98 94 85 69 44
1 4 9 16 25
-3 -5 -7 -9
2 2 2
John
Egw to Beta kai to Sigma
My calculator said it, I believe it, that settles it
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