Finding the rule behind a table

Difficulty Stretch · Set qoi68o

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1
x goes 1, 2, 3, 4 and the rule gives 27, 34, 41, 48. What does the rule multiply x by?
2
x goes 1, 2, 3, 4 and the rule gives 36, 44, 52, 60. What does the rule multiply x by?
3
x goes 1, 2, 3, 4 and the rule gives 7, 12, 17, 22. What does the rule multiply x by?
4
x goes 1, 2, 3, 4 and the rule gives 22, 28, 34, 40. What does the rule multiply x by?
5
x goes 1, 2, 3, 4 and the rule gives 10, 18, 26, 34. What does the rule multiply x by?
6
x goes 1, 2, 3, 4 and the rule gives 23, 28, 33, 38. What does the rule multiply x by?
7
x goes 1, 2, 3, 4 and the rule gives 22, 29, 36, 43. What does the rule multiply x by?
8
x goes 1, 2, 3, 4 and the rule gives 28, 34, 40, 46. What does the rule multiply x by?
9
x goes 1, 2, 3, 4 and the rule gives 30, 32, 34, 36. What does the rule multiply x by?
10
x goes 1, 2, 3, 4 and the rule gives 22, 26, 30, 34. What does the rule multiply x by?
11
x goes 1, 2, 3, 4 and the rule gives 13, 23, 33, 43. What does the rule multiply x by?
12
x goes 1, 2, 3, 4 and the rule gives 7, 13, 19, 25. What does the rule multiply x by?
13
x goes 1, 2, 3, 4 and the rule gives 11, 15, 19, 23. What does the rule multiply x by?
14
x goes 1, 2, 3, 4 and the rule gives 33, 43, 53, 63. What does the rule multiply x by?
15
x goes 1, 2, 3, 4 and the rule gives 38, 46, 54, 62. What does the rule multiply x by?
16
x goes 1, 2, 3, 4 and the rule gives 33, 43, 53, 63. What does the rule multiply x by?
17
x goes 1, 2, 3, 4 and the rule gives 15, 23, 31, 39. What does the rule multiply x by?
18
x goes 1, 2, 3, 4 and the rule gives 29, 37, 45, 53. What does the rule multiply x by?
19
x goes 1, 2, 3, 4 and the rule gives 28, 38, 48, 58. What does the rule multiply x by?
20
x goes 1, 2, 3, 4 and the rule gives 20, 25, 30, 35. What does the rule multiply x by?

What is in this set

The numbers in this set run from 1 to 70.
A careful solution takes 2 written steps on average.
The mistake this set invites most often, in 100% of the problems: the first output was read off as the multiplier; the multiplier is the step between one output and the next.
Answers are a whole number.

Drawing 240 problems from this page produced 162 different ones, 68% — so a sheet of 20 is a new sheet almost every time.

The same skill, harder or easier

We would put this in front of a grade 7 class. That is our judgement, not a standard, and it is printed here so you can disagree with it. Everything else we put in that year.