Question

John has taken up a project for fixing wallpaper on the walls of all the room in a hotel. Each wall requires $7\frac{1}{4}$ of paper to cover the entire wall. John had 628 wallpaper in total and got 19 wallpaper torn in the entire process. Assuming that each room in the hotel are identical and have exactly four walls to cover, then how many rooms does the hotel have?

• A. 21
• B. 29
• C. 42
• D. 84

Answer 1

The correct option is D 84

Step I : Underline key words/facts

John has taken up a project for fixing wallpaper on the walls of all the room in a hotel. Each wall requires $7\frac{1}{4}$ of paper to cover the entire wall. John had 628 wallpaper in total and got 19 wallpaper torn in the entire process. Assuming that each room in the hotel are identical and have exactly four walls to cover, then how many rooms does the hotel have?

Step II : Recognize the variable

Let the number of rooms be 'r'.

Step III : Form Equations to solve

John had 628 wallpaper in total and got 19 wallpaper torn

Therefore, the total number of wallpaper he used = 628 - 19 = 609

We also know, he used exactly $7\frac{1}{4}$ of paper to cover an entire wall.

Therefore, total number of walls before John runs out of wallpaper is given by

$7\frac{1}{4}r=609$

$\frac{29}{4}r=609$

$r=84$