Question

Directions:
Study the following information carefully and answer the questions based on it. Seven friends A, B, C, D, E, F and G are sitting in a straight row, all facing north. The positions are numbered 1 to 7 from the left end to the right end. (i) C sits at the extreme right end of the row. (ii) There are exactly three persons sitting between C and A. (iii) B sits immediately to the left of A. (iv) D sits at the extreme left end of the row. (v) E is not sitting adjacent to A. (vi) F sits immediately to the right of E.

How many persons sit between B and F?

• A. Two
• B. Three
• C. Four
• D. One

Hint:

Once you know exactly where B and F sit, use the simple gap formula (difference of positions minus one) instead of counting seat by seat.

Answer 1

The Correct Option is B

Step 1: Re-derive the needed seats using the anchor equation: C = 7 (clue i), and $7-p_A-1=3 \Rightarrow p_A=3$ (clue ii), so B = 2 (clue iii, immediately left of A).
Step 2: For the remaining positions 4, 5, 6 (E, F, G), clue (vi) requires F = E + 1, giving candidate pairs (E,F) = (4,5) or (5,6); clue (v) removes E = 4 (adjacent to A at 3), so E = 5 and F = 6.
Step 3: Apply the "persons between two seats" formula: for positions $x$ and $y$ with $x<y$, the number of people strictly between them is $y-x-1$.
Step 4: Here B is at position 2 and F is at position 6, so the count is $6-2-1=3$.
Step 5: This rules out "Two", "Four" and "One" as options, since none of them equals the computed value of 3.
Correct option: Three