Difficulty: Medium
Correct Answer: PPPPPPQ
Explanation:
Introduction / Context:
This pattern question uses only two letters, P and Q, in seven-letter strings. The sequence PQPPPPP, PPQPPPP, PPPQPPP, PPPPQPP, PPPPPQP shows a shifting position of the single Q among many P letters. Such questions test the ability to track a moving element in a fixed-length string and recognise how it progresses from one step to the next.
Given Data / Assumptions:
Concept / Approach:
We identify the position of Q in each term, counting from the left, and check how its position changes from one term to the next. If the Q consistently moves by one position on each step, the next term will be the one where Q occupies the next position in line. Because the length of the string is fixed, this pattern will end when Q reaches the final position.
Step-by-Step Solution:
In PQPPPPP, Q is in position 2.In PPQPPPP, Q is in position 3.In PPPQPPP, Q is in position 4.In PPPPQPP, Q is in position 5.In PPPPPQP, Q is in position 6.Thus the Q shifts one place right at each step: 2, 3, 4, 5, 6.The next position for Q must therefore be position 7, meaning Q should be at the last position and all preceding characters should be P.This gives the term PPPPPPQ.
Verification / Alternative check:
We can write the positions of Q as a numeric series: 2, 3, 4, 5, 6, ?. It is obviously an arithmetic progression with a common difference of +1. Extending this predicts 7, which confirms that Q should be at the far right. No changes to the number of P letters occur throughout the sequence, so the pattern remains exactly one Q and six P letters per term.
Why Other Options Are Wrong:
QPPPPPP would place Q at position 1, which would jump back to the left instead of moving further right. Repeating PQPPPPP or PPQPPPP, as in options b and d, would restart earlier positions and ignore the steady progression. Thus, these options break the clear rule of shifting Q one position to the right in each term and are therefore incorrect.
Common Pitfalls:
Candidates sometimes miscount positions, especially in longer strings, or fail to notice that there is always exactly one Q. Others look only at the first or last letters and miss the internal movement. Carefully counting from left to right and recording the exact position of Q in each term helps avoid these mistakes.
Final Answer:
PPPPPPQ
Discussion & Comments