How many children are there between A and B in a row of children?
Statement I: A is seventeenth from the left in the row.
Statement II: B is exactly in the middle, and there are ten children to his right as well as to his left.
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → The data in both statements I and II together are necessary to answer the question.
To count the children between A and B, both their positions must be known from the same end of the row.
Statement I alone gives A's position (17th from the left) but says nothing about B, so it is not sufficient.
Statement II alone gives the row as \(10+1+10=21\) children with B 11th from the left, but says nothing about A, so it is not sufficient.
Both together: A is 17th and B is 11th from the left, so there are \(17-11-1=5\) children between them. The two statements are needed together.
