You would use the bottom right box :)
Answer:
10⁴ seconds
Step-by-step explanation:
Given that,
A person breathes
in about cubic meters of air per second.
We need to find time taken to breathe 2.5 cubic meters of air.
In 1 sec =
m³ of air breathe
Let in x seconds, 2.5 m³ of air taken by the person.

Hence, in 10⁴ seconds 2.5 m³ of air is taken by the person.
The answer is d which is 6/5