Question

The length, $l$ meters, of a garden is 78.5m, correct to the nearest half meter.
Correct this statement about the value of $l$.
$...................⩽l⩽...............$

Answer 1

Hint: Add & subtract half meter to get the range.

Complete step-by-step answer:
It is given that the length of the garden which is 78.5m is correct up to half meter.
So, the range of length of the garden can be written as $\left(78.5\pm {\displaystyle \frac{1}{2}}\right)m$

So,
$$\begin{gathered} l_1=78.5-{\displaystyle \frac{1}{2}}=78.5-0.5=78m \\ {l}_2=78.5+{\displaystyle \frac{1}{2}}=78.5+0.5=79m \end{gathered}$$
So, the length of the garden is greater than equal to 78m and less than equal to 79m.
Therefore length $\left(l\right)$ of garden correct up to half meter is written as
$78⩽l⩽79$
So, this is the required answer.

Note: In these types of questions, add and subtract half meter to the value given in question, so that we can get the required range.