1) B

If height path the end of first year = 1m, then height at start of second year would also = 1m

Maximum theoretical height of tree = 30m

Difference between 30 and 1 = 30 – 1 = 29m

Since the growth will be 10% of the difference, growth in second year = 10% of 29 = 2.9 m

Height at the start of third year = 1 + 2.9 = 3.9m

Difference = 30 – 3.9 = 26.1m

10% = 2.61m

Total height = 3.90 + 2.61 = 6.51 m

To the nearest 10 cm, this will be 6.5 m

So the answer would be B