Question

find the sum of 7+14+21+____+490​

Answer 1

Answer:

105

Step-by-step explanation:

7

14

21=105 add the sum

Answer 2

Answer:

THE SUM =17,395

first we will find the number of terms in this AP.

an = a+(n-1)d

490=7+(n-1)7

490=7n

n=70

there are 70 terms in this AP.

Now as per the question,

Sum(n)=n/2(2a+(n-1)d)

35×496

=17,395

THE SUM =17,395