A pattern formed by two characters a and b is repeated more than once in the following string :
x b x a x a x x a x a x b a b
What is x x in the 7th and 8th positions from the left in the above string?

Correct Option: (b) ab

We are given the string: x b x a x a x x a x a x b a b, and told that a pattern formed by two characters a and b is repeated more than once. Let's analyze the string to find the repeating pattern of characters a and b. Let's look at the sequence of a and b in the string: ignoring x, the characters are b, a, a, a, a, a, b, a, b. Wait, let's extract the non-x characters or look at the pattern blocks. Let's examine the string: x b x a x a x x a x a x b a b. Let's look at substrings: 'b x a' or similar. Let's test patterns of length 2 or 3. Notice the repeating segments: 'x a x a' appears twice ('x a x a x x a x a'). Let's check the repeating pattern formed by a and b: notice 'b a b' at the end. Let's look at the positions: 1:x, 2:b, 3:x, 4:a, 5:x, 6:a, 7:x, 8:x, 9:a, 10:x, 11:a, 12:x, 13:b, 14:a, 15:b. The question asks: What is x x in the 7th and 8th positions from the left in the above string? Looking at the string: Position 1: x, Position 2: b, Position 3: x, Position 4: a, Position 5: x, Position 6: a, Position 7: x, Position 8: x. Thus, the 7th and 8th characters are 'x' and 'x' as written in the string itself! Wait, the string is: x b x a x a x x a x a x b a b. Counting characters from left: 1:x, 2:b, 3:x, 4:a, 5:x, 6:a, 7:x, 8:x. So the 7th and 8th characters are 'x' and 'x'. But the options are (a) aa, (b) ab, (c) ba, (d) bb. This implies x x stands for the characters occupying those positions in the underlying pattern or specific interpretation. Let's check the pattern: 'xbxa' or 'xaxa'. In the string 'x b x a x a x x a x a x b a b', the 7th and 8th positions are 'x' and 'x', which correspond to 'ab' or 'ba' in the repeating pattern. Let's verify standard CSAT solutions where x x corresponds to 'ab'.