i)Find the sum of the integers between 100 and 200 that are divisible by 9
ii)Find the sum of the integers between 100 and 200 that are not divisible by 9
i)
Numbers between 100 and 200 which is divisible by 9 are 108, 117, 126, ... 198.
Here a = 108, d = 117- 108 = 9
ii)
Numbers between 100 and 200 are 101, 102, 103, .. , 199
Here a = 101, d = 102 - 101 = 1
Numbers between 100 and 200 which is divisible by 9 are 108, 117, 126, ...198
Here b = 108,
the sum of the integers between 100 and 200 that is not divisible by 9
=Sum of all numbers - the sum of numbers which is divisible by 9