Question

What is the answer ?

Answer 1

X= 0,77 cm

Explanation:

if you count the millimeters mark (the little notches upwards) you count more than seven but less then eight.
Since the two scales coincides on the fifth one, for every signs (three) beyond the five you have to remove 0,1 mm fom eight. so 8,0 mm - 0,3 mm= 7,7 mm