1.
If logea,logeb,logec\log_e a, \log_e b, \log_e c are in an A.P. and logealoge2b,loge2bloge3c,loge3clogea\log_e a - \log_e 2b, \log_e 2b - \log_e 3c, \log_e 3c - \log_e a are also in an A.P., then a+b+ca + b + c is equal to: