7. While measuring the length of a knitting needle, the reading of the scale at one end is 3.0 cm and at the other end is 33.1 cm. What is the length of the needle?
Reading of the scale at one end = 3.0 cm.
Reading of the scale at the other end = 33.1 cm.
Length of the scale = 33.1 cm - 3.0 cm = 30.1 cm