81. 9215-!-item-!-187;#058&006304
If each term in the sum a1 + a2 + . . . + an is either 7 or 77 and the sum equals 350, which of the following could be equal to n ?
(A) 38
(B) 39
(C) 40
(D) 41
(E) 42
ANS:C
請麻煩幫幫我....我真的看不懂這題到底想要幹麻....