4. Brothers Marko and Petar collect comics. In their collection, they currently have 67 comics, of which Marko has read 34, and Petar 27. How many comics have not been read if both brothers have read 15 of the same comics?
First method:

If both brothers have read 15 of the same comics, then Marko has read $34-15=19$ comics that Petar has not read, and Petar has read $27-15=12$ comics that Marko has not read. 2 POINTS When the comics read only by Marko, only by Petar, and by both brothers together are added up, the result is $19+12+15=46$. 2 POINTS

$67-46=21$

1 POINT

21 comics have not been read.

1 POINT

TOTAL 6 POINTS

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