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One-half of a roll of wallpaper covers 1/10th of a wall. How many rolls of wallpaper are needed to cover half the wall? (a) 2/10 (b) 2 1/12 (c) 5 (d) 10

User Endre Simo
by
6.4k points

2 Answers

3 votes

Answer:


2(1)/(2) rolls of the wallpaper will cover half the wall

The correct option is (b) 2 1/2

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 Ă— 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,
x rolls of the wallpaper will cover 1/2 of the wall


x =(1/2 * 1)/(1/5)


x =(5)/(2)


x =2(1)/(2)

Hence,
2(1)/(2) rolls of the wallpaper will cover half the wall

User Tavon
by
6.9k points
2 votes

Answer:

2 1/2 rolls

Explanation:

rolls : walls = (1/2) : (1/10) = ? : (1/2) = 5/2 : 1/2 (multiply by 5, since 1/2 = 5/10)

It takes 5/2 rolls = 2 1/2 rolls to cover half the wall.

User Yottatsa
by
7.0k points
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