the total number of ways  of selecting  two  number  from  the set  {1,2,3,4,…..3n}
Channel: Doubtnut
Date: 11/11/2021

the total number of ways  of selecting  two  number  from  the set  {1,2,3,4,…..3n} so that  their  sum divisible  by 3 is equal  to -