A tree in each year grows 4cm less than it grew in previous year. If it grew 1 metre in the first year, in how many years will it have ceased growing and what will be its height then,
1300
First term = a = 100 c.m.
Common Difference = d = - 4
Tn = 0
⇒ a + (n - 1)d = 0
⇒ 100 + (n - 1)(- 4) = 0
⇒ 25 + (n - 1)(- 1) = 0
⇒ 25 - n + 1 = 0
⇒ - n = - 26
⇒ n = 26