
Rounded Roots
Problem
A special number machine will accept any whole number, find its square root and then output the result rounded off to the nearest whole number.
For example,
| Input | Output | |||
| 32 | 6 |
If the output is 6, one possible input is 32, but which other numbers could have gone into the machine to give an output of 6?
Solution
5.52 = 30.25, so
30
5.5 and 6.52 = 42.25, so
43 > 6.5.
Hence the solution set is 31, 32, 33, ..., 42
Find the solution sets for each of the integers from 1 to 10.
Is there a rule connecting the output with the solution set?
Problem ID: 47 (May 2001) Difficulty: 2 Star
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