The Government of India is planning to plant 6000 trees in various parts of cities within a span of 10 years. They planted 500 in the first year and increased by 20 every year. After 10 years, how much more trees they will have to plant in order to reach the required target?

Answer 1

a = 500
d = 20
S10 = 10/2 (2a+9d)
subtract S10 from 6000