The sum of all those terms, of the arithmetic progression 3, 8, 13, …., 373, which are not divisible by 3, is equal to _____.
Explanation
Given A.P. is 3,8,13,…,373
Using
, we get:
Sum of complete A.P. =
2n(a+l)=275(3+373)=14100
Now, the numbers divisible by 3 are 3,18,33,…,363
Using
, we get:
So sum of this A.P. =
2k(a+l)=225(3+363)=4575
Hence, the required sum is
Explanation
Given A.P. is 3,8,13,…,373
Using
, we get:
Sum of complete A.P. =
2n(a+l)=275(3+373)=14100
Now, the numbers divisible by 3 are 3,18,33,…,363
Using
, we get:
So sum of this A.P. =
2k(a+l)=225(3+363)=4575
Hence, the required sum is