Question

In a slide show programme, the image on the screen has an area $900$ times that of the slide. If the distance between the slide and the screen is $x$ times the distance between the slide and the projector lens, then

• A. $x=30$
• B. $x=31$
• C. $x=500$
• D. $x=1/30$

Answer 1

The correct option is B $x=31$

$m=30$
$v+u=xu$
or $\frac{v}{u}+1=x$ or $m+1=x$
or $x=31$.