Answer:
Given a = 14
d = 7
an = 196
a + ( n - 1 ) d = 169
14 + ( n - 1 ) 7 = 169
( n - 1 ) 7 = 182
n - 1 = 26
n = 26 + 1
n = 27
Sum = n / 2 ( a + an )
27 / 2 ( 14 + 196 )
27 ( 105 )
2835
Answer:
2835.
Step-by-step explanation:
The first integer divisible by 7 is 14 and the last one is 196 ( as 7*28) = 196).
We have an Arithmetic series here where each term is increased by 7 to get the next one.
The number of terms (n) = (196 - 14)/ 7 + 1 = 26 + 1 = 27.
The formula for the sum of n terms = (n/2)(a + l) where a = first and l = last term.
So the answer is :
(27/2)( 14 + 196)
= 13.5 * 210
= 2835.
