Question

The length of the wing of an insect in a picture is 4 cm. The scale of the picture is 20:1. What is the real length of the insect’s wing?

Answer 1

0.2cm
Working;
Since the picture is a magnification of the insect, the real insect is smaller than the picture

If 20cm on the picture is equivalent to 1 cm of the real insect, then;
$\frac{4*1}{20} =0.2cm$

Answer 2

If you would like to know the real length of the insect's wing, you can calculate this using the following steps:

1/20 of 4 cm = 1/20 * 4 = 4/20 = 1/5 cm = 0.2 cm

The correct result would be 0.2 cm.