Seven sisters, A, B, S, D, R, L and G, are standing in a row facing North. L is standing to the immediate right of R, who stands fourth to the right of G. Only S stands exactly between B and D. D stands at the middle position.
Who stands at the rightmost position?
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → A
Facing North, a sister’s right is the right side of the row. Number the places 1 to 7 from the left.
D is in the middle: D in place 4
Only S is between B and D, so S is next to D and B is next to S: either B 2, S 3 or S 5, B 6
R is fourth to the right of G and L is next to R on the right, so G, R and L need places g, g + 4 and g + 5
If S and B are in places 5 and 6, the free places are 1, 2, 3 and 7; no g gives free places g + 4 and g + 5. This case fails
So B is in place 2 and S in place 3. The free places are 1, 5, 6 and 7, and g = 1 works: G 1, R 5, L 6
A takes the last place, 7. The row reads G, B, S, D, R, L, A, so the rightmost sister is A
