The number of 3-digit odd numbers, whose sum of digits is a multiple of 7, is\_\_\_\_
Answer: 63
Solutions · 1
Official solution
*(The extracted PDF text for this item's worked solution was garbled and merged with adjacent questions; the verified answer is 63, obtained by counting 3-digit numbers abc with c∈{1,3,5,7,9} and a+b+c≡0(mod7).)*