The first step in solving this problem is to convert all the numbers to the same standard of measure. Since the answer required is in inches, that is the unit to which you would convert all of the data.
To convert feet to inches, you use 1 foot = 12 inches and multiply all foot data by 12, and the problem becomes: (4 x 12) inches + 8 inches + (6 x 12) inches + 10 inches
48 inches + 8 inches + 72 inches + 10 inches Add all of the numbers to arrive at 138 inches.