A fireman used a ladder with 54 rungs The rungs on the ladde

A fireman used a ladder with 54 rungs. The rungs on the ladder were 13 in. apart and 1.5 in. thick. What is the distance from the bottom of the lowest rung to the top of the highest rung?

In between the 1st and 54th rungs there are 53 gaps each of 13 inch and all total 54 rungs each of 1.5 inch thicker, so, the required distance from bottom of 1st rung to the top of 54th rung will be

D = (53×13+54×1.5) inch