Question

After a robot vacuum is fully charged, it can run for 15 minutes. It can vacuum 1/2 square foot every second. Can a fully charged robot clean a room that is 400 square feet without recharging?

Answer 1

Answer:

The robot can clean the room without recharging.

Step-by-step explanation:

Given:

After a robot vacuum is fully charged, it can run for $15$ minutes.

The robot cleans $\frac{1}{2}$ square foot every second.

To find: If the charged robot can clean a room that is $400$ square feet without recharging.

Solution:

Area cleaned by the robot in $1$ second $=\frac{1}{2}$ square foot.

We know that, $1$ minute $=60$ seconds.

So, $15$ minutes $=15\times 60=900$ seconds.

Now, area cleaned by the robot in $900$ seconds $=\frac{1}{2} \times 900=450$ square feet.

The area to be cleaned is $400$ square feet.

Hence, the robot can clean the room without recharging.