7 countries: ABCDEFG
B - ? - ? - C
C =/= 7
A < B
No (DE)/(ED)
F = 4/5
Diagram:
A < (B - ? - ? < C) So C = 5/6
If C = 5,
-A--B-D/E-F--C-(E/D&G)
-1--2--3--4--5--6--7
If C = 6,
-(A&?)--B--(F&?)--C--?
-1--2--3--4--5--6--7
1. Which one of the following could be the order in which Jandra visits the countries, from first to last?
(B) ED together
(C) Only 1 between B & C
(D) D * 2
(E) C = 7
Answer : (A)
2. If Jandra visits China fifth, each of the following could be true EXCEPT:
-A--B-D/E-F--C-(E/D&G)
-1--2--3--4--5--6--7
Answer : (B)
3. If Jandra visits Djibouti second, but she does not visit Fiji fourth, each of the following could be true EXCEPT:
-A--D--B-G/E-F--C-E/G
-1--2--3--4--5--6--7
Answer : (D)
4. If Jandra visits Australia and Bahrain first and second on her trip, respectively, how many different orders are there in which she can visit the seven countries?
-A--B-D/E-F--C-(E/D&G)
-1--2--3--4--5--6--7
Orders: ABDFCEG ABDFCGE ABEFCDG ABEFCGD
Answer : (D)
5. If the condition that China cannot be visited last is removed, and Jandra takes advantage of the opportunity to visit China last, but all other conditions remain in effect, which one of the following could now be a complete list of countries, any one of which could be visited third?
C can be 7, then If C = 7,
-?--?--?---B--F--?--C
-1--2--3--4--5--6--7
(E/D-A-D/E)------G
-(A+E/D+G)-----D/E
3 = A/D/E/G
Answer : (C)
-- by 会员 taoransk (2010/11/7 12:07:19)