The outside diameter (od) of a pipe is 4 9/32 inches. The walls are 7/32 inches thick. find the inside diameter. Please explain how you got your answer.​

The inside diameter would be the outside diameter minus 2 of the wall thicknesses.

4 9/32 - (2 x 7/32)

Simplify:

4 9/32 - 14/32

Because 14/32 is larger than 9/32 change one of the hole numbers to a fraction: 1 = 32/32

rewrite 4 9/32 as 3 41/32

Now subtract:

3 41/32 - 14/32 = 3 27/32 inside diameter.

the answer to your question is minor arc.