Question

Subtract 2 hours, 20 minutes from 4 hours, 10 minutes.

Answer 1

Easy  1 hour and 50 minutes hope this helps 

Answer 2

So, Lets turn these into Minutes to make this easier. 

2 hrs, 20 min would be 140 min. 
4 hrs, 10 min would be 250 min.

Now subtract 140 from 250. 

250 - 140 = 110 

So, 1 hr and 50 min. :)