.
It is not possible to answer the problem's question as it is worded,
because the question is posed INCORRECTLY.
The composer of this problem deserves the lowest possible score for producing this FAKE problem.
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The solution by @MathLover1 is TOTALLY INADEQUATE.
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Technically, if the statement says that the error of the measure of the length x
is "k" percents and "m" is the measured value, it means that
| x - m | = 0.01*k*x.
In our case, it takes the form
| x - 35 | = 0.74x.
+----------------------------------------------------------+
| NOTICE the ABSOLUTE VALUE sign in this equality (!) |
+----------------------------------------------------------+
So, we have TWO equations for x
(a) x - 0.74x = 35, which implies 0.26x = 35, x = = 134.6 meters (rounded),
or
(b) x + 0.74x = 35, which implies 1.74x = 35, x = = 20.1 meters (rounded).
Thus you have TWO possible answers, and from the description, there is NO WAY to select one unique answer.