Answer:
10 cm overlap required to make a 30 cm long strip.
Step-by-step explanation:
Given:
Four paper strips of the same length.
Two of them glued together with a 4 cm overlap to make a new strip which is 36 cm long.
To find:
Overlap required to make a strip which is 30 cm long = ?
Solution:
First of all, let us understand the concept of overlap.
Please refer to the attached image.
Let length of each strip be [tex]x[/tex] cm.
Given that there is 4 cm overlap resulting in new strip of length 36 cm.
The overlapping length is counted only once as clear from the figure attached.
So, Let us try to find the equation:
[tex]x +(x-4) = 36\\\Rightarrow 2x=40\\\Rightarrow x = 20\ cm[/tex]
i.e. each strip length is 20 cm.
Now, let us assume, an overlap of 'y' cm is to be made to make a new strip of 30 cm.
The equation will be:
[tex](20-y)+20 =30\\\Rightarrow y = 40-30\\\Rightarrow y = 10\ cm[/tex]