Answers

2016-07-01T10:06:10+08:00
Sn=n/2(A1+An)
Sn=10/2(1+10)
S10=5(11)
S10=55
2 4 2
Thanks for posting answer with proper solution:-)
tnx for d solution
2016-07-02T14:10:00+08:00
55 is the sum of 1st 10 positive integers

1 5 1