Question.

11 hours

(1 hr 40 min) + (80min) + (90 min) + (1 hr 20 min) + (110 min)  =  ?

Rearrange, placing the hours together and the minutes together:

=  (1 hr + 1 hr) + (40 min + 80 min + 90 min + 20 min + 110 min)

=  (2 hr) + (340 min)

Change minutes into hours by finding the number of full hours in 340 minutes. Divide the number of minutes by 60:  

340 / 60  =  5.6666...

This means that there are 5 full hours in 340 minutes.  Multiplying 5 x 60  =  300 minutes.

Subtracting 300 minutes from 340 minutes leaves 40 minutes.

So 340 minutes is 5 hours and 40 minutes.

(2 hr) + (340 min)  =  (2 hr) + (5 hr 40 min)  =  (2hr + 5 hr) + (40 min)  =  7 hr 40 min

convert 1 hour 40 mins and 1 hr 20 mins into minutes (100 minutes and 80 minutes)

100+80+90+80+110

460 minutes.

Convert to hours.

460/60

7.666666.... hours

7 hours = ? minutes (7*60 = 420 minutes)

(460 - 420 = 40) 40 is the minutes left over.

So it's 7 hours and 40 minutes.