Answer:
Lewis’ friend walked a total of 0.36 mile with him
Explanation:
Here, we are told Lewis walked 9/10 of a mile. The total amount of distance he has walked in miles will be 9/10 * 1 = 0.9 mile
Now, his friend walked a total of 2/5 of the way with him, the number of miles this friend had walked will thus be 2/5 * 0.9 = 0.36 mile