20-02-2013, 07:16 PM
yes great answer bro
formula is
(n(n+1)/2)=66
n^2+n=132
n^2+n-132=0
(n-12)(n+11)=0
n=12;n=-11
ans is 12
11 is not answer because -11 is not proper
formula is
(n(n+1)/2)=66
n^2+n=132
n^2+n-132=0
(n-12)(n+11)=0
n=12;n=-11
ans is 12
11 is not answer because -11 is not proper
Good!