18. 두 수열 {an},{bn}\{a_n\},\{b_n\}{an},{bn}에 대하여 ∑k=110ak=∑k=110(2bk−1),∑k=110(3ak+bk)=33\sum_{k=1}^{10}a_k=\sum_{k=1}^{10}(2b_k-1),\quad\sum_{k=1}^{10}(3a_k+b_k)=33∑k=110ak=∑k=110(2bk−1),∑k=110(3ak+bk)=33일 때, ∑k=110bk\sum_{k=1}^{10}b_k∑k=110bk의 값을 구하시오. [3점]