Need help! I need a short answer :)

If f(x) and g(x) are inverse functions of each other, which of the following shows the graph of f(g(x)

How many 3-digit numbers can you write using only digits 1 and 7? (of course, digits can repeat.) how many 3-digit numbers can you write using only digits 1 and 7? (of course, digits can repeat.)

Keith runs 5 miles in 38 minutes. at the same rate, how many miles would he run in 57 minutes