Question

step–by–step explained​

Answer 1

Answer:

5 hours

Step-by-step explanation:

please mark as brainliest answer

Answer 2

Step-by-step explanation:

Let x minutes be the duration of period when the school has 9 periods a day. Then

Number of periods 8 9

Duration of periods (in minutes) 45 x

Clearly, more the periods, less will be the duration of the period.

So, it is a case of inverse proportion.

∴8×45=9×x

⇒x=

9

8×45

=40

Hence, the duration of period is 40 minutes.