ANSWER:

Given Puzzle: 5,7 = (31) ; 8,3 = (81) ; 9,8 = (72) ; 7,7 = (X)

Solution #1: (No options provided!)

1: 5, 7 = 31

57 – 31 = 26

2: 8, 3 = 81

83 – 81 = 2

3: 9, 8 = 72

98 – 72 = 26

So, the series are like this: 26, 2, 26, 2

Now we want the output 2.

So,

4: 77 – X = 2

X = 77 – 2

X = 75

Solution #2: (With options provided!)

1: 5, 7 = 31

5 (Odd), 7 (Odd) = 3 (Odd), 1 (Odd)

2: 8, 3 = 81

8 (Even), 3 (Odd) = 8 (Even), 1 (Odd)

3: 9, 8 = 72

9 (Odd), 8 (Even) = 7 (Odd), 2 (Even)

So, Next Number should be (Odd), (Odd)

4: 7, 7 = X

Options given are (A). 97, (B). 87, (C). 82 and (D). 45, so the answer should be (A). 97.

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