At what distance from the fulcrum should a force of 1 N be applied

At what distance from the fulcrum should a force of 1 N be applied to balance the 4.5 N force acting on the lever and having an arm 15 cm long?

As we know, in order to determine one of the parameters of the lever (whether the length of the arm, whether the force acting on the lever arm), it is possible to use the formula known from the school curriculum:

F1 * L1 = F2 * L2.

Let us determine what value should be equal to the length of the arm, on which a force equal to 1 N acts, so that the lever is in equilibrium, if from the condition of our problem we know for sure that a force of 4.5 N acts on the other arm 15 cm long:

1 * L1 = 4.5 * 15;

L1 = 67.5.

Answer: 67.5 centimeters.