Respuesta :

22 hours and 39 minutes

Answer:

22 hours 39 minutes

Step-by-step explanation:

To simplify the expression, we must know the relationship between minutes and hours.

Since 60 minutes make 1 hour, then 99 minutes will be equivalent to

= 99/60

= 1.65 hours

= 1 hour 39 minutes

As such,

21 hours 99 minutes

=  21 hours + 1 hours 39 minutes

= 22 hours 39 minutes