A collection of 36 cards consists of 4 sets of 9 cards each. The 9 cards in each set are number1 through 9. If one card has been removed from the collection, what is the number on that card?
(1) The units digit of the sum of the numbers on the remaining 35 cards is 6.
(2) The sum of the numbers on the remaining 35 cards is 176
請問一下(1)為什麼充份呢?
