Question

问两道英语奥数题

1. There are 9 cards with 1,2,3,4,5,6,7,8,9 respectively. Tow people picks up one card by turns, who firstly use threes cards of the nine cards to gets 15 by addition will be winner. Then does the people who picks first has the strategy to ensure his win?
2. A, Band C will run for the captain and 120 students will vote for them, and every student can only vote one of these three and can't give up vote, and now among the first 100 tickets, A gets 45 tickets and B gets 35 tickets, if A wants to be the captain, how many tickets at least must A need to get?

Answer 1

1.Because 9 plus 6 or 8 plusis 7 is 15, so who first get one of the two pairs will ensure win. So please pick the card with bigger number.
2.Because C is the certain failure(he only get 20 votes among the first 100 votes), so the captain will apprear between A and B. There are 20 votes left. If A get 5 votes and B get 15 votes, they will get deuce. So a at least need 6 votes to get. In the other word, If the three are deuce, they should get 40 votes each other. Now there are 20 votes for C in the first 100 votes. If A and B get deuce, they will get 50 votes each other. So if a wants to win, he need 51 votes. Now A has got 45 votes, so he need at least 6 votes(51 minus 45) to get.