Question

Adding 18 minutes 40 second and 12 minutes and 20 second we get

Answer 1

Answer:

 56:37

Step-by-step explanation:

18 mint 40 sec:12 mint 20 sec

=18*60+40 sec : 12*60+20

= 1120 : 740

= 224 : 148

= 112 : 74

= 56 : 37