paste is pretty handy here but it'll punish you if the number of values is unequal:

$ paste -d' ' myFile{1,2}

1 10 10

2 20 11

3 30 12

4 40 13

5 50 14

6 60 15

 16

If you wanted to arbitrarily limit the lines used in the second file to the first, you can, it's just going to be a bit slower and use more RAM (not that it matters on such a small data set).

$ paste -d' ' myFile1 <(head -n$(cat myFile1 | wc -l) myFile2)

1 10 10

2 20 11

3 30 12

4 40 13

5 50 14

6 60 15