which means if the answer was $50,$ then the error should not exceed $500\mathrm{.}01=+-0\mathrm{.}5!$

if the answer was $230,$ then the error should not exceed ${230}^{**}0\mathrm{.}01=+-2\mathrm{.}3!$

if the answer was ${2\mathrm{.}31467}^{**}101-3,$ then you should enter this value: $0\mathrm{.}00231467,$ not this $0\mathrm{.}0023!!!$

Now, Read the question carefully:

For the following engineering office, you are asked to calculate the llluminance levels at the points of interests A B and C$.$

If the Office height is ${10}^{\text{'}}$ and the height of the work surfaces $($points of interests$)$ of desk A$.$ Desk B and the drafting table $C$ is $3^{\text{'}}.$ The horizontal spacing $(dx)$ between the Points A and $B$ is the same as the spacing distance between the points A and $C.$

Notice that the drafting table is tilted with an angle $($Delta$).$ where $=5$ degrees.

According to the following candlepower distribution curve of the light source, Find:

The light intensity directly under the light fixture is: ca$.$

The llluminance at point A equals $=$ fc$.$

If the angle $$ is $40,$ Then the llluminance at point $B$ equals $=$ fc$.$

The llluminance at point $C$ equals $=$ fc$.$

The illuminance level at point B was insufficient, so$,$ another light source was added to the right of the perpendicular line at point $B$ as shown in the figure below.