The long piece is 4 times the length of the short piece. 
Short piece = 1 time
Long piece  = 4 times
--------------------------------
Full rope  =  5 times
                                   5 times = 70 inches 
Divide each side by 5 :    1 time = 14 inches
Short piece = 1 time = 14 inches
Long piece = 4 times = 4 x 14inches = 56 inches
Check:
Ratio of long to short  =  56inches / 14inches  = 4
Sum of both pieces =  (56 + 14)  =  70 inches
                                                                         yay !