Answer:
1 1/9 miles
Step-by-step explanation:
If john swims 5/12 of a mile in 3/8 of an hour, then;
5/12 miles = 3/8 hours
TO get the number of miles he swims in an hour, we will say;
x miles = 1 hour
Equating both expressions
5/12 miles = 3/8 hours
x miles = 1 hour
Cross multiply
3/8 x = 5/12
3x/8 = 5/12
3x * 12 = 5 * 8
36x = 40
x = 40/36
x = 10/9
x = 1 1/9
The amount he swims in an hour is 1 1/9 miles