To paste the room and the corridor bought 25 rolls of wallpaper. How many rolls will be used for pasting the walls of the corridor if it needs 4 times less wallpaper than for a room?
In this problem, the total number and the relationship between the two quantities is known. Denote by x rolls the amount that went to pasting the corridor. Then 4 rolls – went for pasting the room. In total, 25 rolls were needed, that is, the sum of x and 4x is 25: x + 4x = 25
Answer: 5 rolls are needed for pasting the corridor.
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