X/4 - 3
(*make sure to write the division in fraction form as shown for algebraic notation)
She would start at the 3 inch mark and count from there.
Answer: 
Step-by-step explanation:

Distribute the negative sign. This basically changes all the signs inside the parentheses.

Combine like terms;

Answer:
27/40
Step-by-step explanation:
There is no picture or diameter/radius measurements, therefore this question cannot be answered properly.