find the sum of all natural numbers between 200 and 400 which are not divisible by 7
Answers
Answered by
3
Answer:
The first term after 200 divisible by 7 is 203. The last term before 400 divisible by 7 is 399. The number of terms = ?
=> l = a + ( n - 1 ) d
=> 399 = 203 + ( n - 1 ) 7
=> 399 - 203 = ( n - 1 ) 7
=. 196 = ( n - 1 ) 7
=> 196 / 7 = ( n - 1 )
=> 28 = ( n - 1 )
=> n = 28 + 1 = 29
Hence the number of terms is 29.
Applying Sum formula we get,
Hence the sum of all the natural numbers divisible by 7 lying between 200 and 400 is 8729.
Answered by
0
Refers to attachment ♡~
Attachments:
Similar questions