Answer :
11 ft + 3 ft = 14 ft
14 ft+ 3 ft = 17 ft
17ft + 3 ft = 20 ft
20ft + 3ft = 23 ft
23ft + 3ft = 26ft
26ft +3 ft = 29 ft
total of 6 years
14 ft+ 3 ft = 17 ft
17ft + 3 ft = 20 ft
20ft + 3ft = 23 ft
23ft + 3ft = 26ft
26ft +3 ft = 29 ft
total of 6 years