Answer:
rolls of the wallpaper will cover half the wall
The correct option is (b) 2 1/2
Step-by-step explanation:
To determine the number of rolls of wallpaper that are needed to cover half (1/2) the wall,
From the question,
One-half of a roll of wallpaper covers 1/10th of a wall.
Hence, we are to determine the number of rolls of wallpaper that are needed to cover 5/10th of the wall. (NOTE: 5/10th of the wall = 1/2 the wall)
Now,
First, we will find the part of the wall that will be covered by one roll of the wallpaper
If one-half of the roll of wallpaper covers 1/10th of the wall.
Then, one roll (two halves) will cover 2 × 1/10th of the wall
= 1/5th of the wall
Hence one roll will cover 1/5th of the wall
Now, for the number of rolls that will cover half (1/2) the wall
If one roll of the wallpaper covers 1/5th of the wall
Then,
rolls of the wallpaper will cover 1/2 of the wall



Hence,
rolls of the wallpaper will cover half the wall