Answer:
19/20 hours
Step-by-step explanation
From the question, we are given the following;
Time taken on History Assignment = 1/5 hours
Time taken to complete English Assignment = 3/4 hrs
Total amount of time spent = 1/5 + 3/4
Total amount of time spent = (4+5(3))/20
Total amount of time spent = (4+15)/20
Total amount of time spent = 19/20
Hence the total time he spent on both assignements is 19/20 hours