Question

$\text{It took 45 minutes to clean a portion of restaurant.}$ $\text{However 'x'}{\text{m}}^2\text{area of restaurant is}\text{still left. To}$ $\text{make the process faster, it is decided to clean every}$
$1{\text{m}}^2\text{of the remaining area in every 0.35 minutes.}$

If 't' is the total time taken to clean the entire restaurant, select the function that represents the total time taken.

• A. x = 45 - 0.35t
• B. x = 45 + 0.35t
• C. t = 45 + 0.35x
• D. t = 45 - 0.35x

Answer 1

The correct option is C t = 45 + 0.35x

Here, total time taken will be the output = t

Number of minutes took to clean a portion of restraurant = 45

$\text{To increase the process it is cleaned at a}$
$\text{rate of}1{\text{m}}^2$ $\text{per 0.35 minutes}$

$\therefore \text{Time taken to clean x}{\text{m}}^2\text{of remaining}$
$\text{area}=0.35x$

$\text{So, total time taken = Number of minutes}$
$\text{taken to clean a portion of restaurant}$
$+\text{time taken to clean remaining x}{\text{m}}^2$

$⟹$ $t=45+0.35x$