7th Class
Mathematics
Related to Competitive Exam
Question Bank
Number and Ranking
question_answer
In the series; 6 4 1 2 2 8 7 4 2 1 5 3 8 6 2 1 7 1 4 1 3 2 8 6 How many pairs of alternate numbers have a difference of 2? Rules: If there are N persons standing in a row and ranks of a person both from the top and from the bottom are Tr and Br, then the rules are (i) \[N=Tr+Br-1\] (ii) \[Tr=(N+1)-Br\]and (iii) \[Br=(N+1)-Tr.\]
A)One
B)Two
C)Three
D)Four
Correct Answer:
B
Solution :
Clearly there are two such pairs only namely (4, 2); (1, 3)