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Q6·CSAT · Prelims 2025

Symbolic operation puzzle (7*24=25)

ReasoningSymbolic OperationsSequence & patternHard

Question

If 724 = 25 and 1216 = 20, then what is 1663 equal to ?

Options

a

70

b

66

c

65

Answer
d

64

Explanation

The operator denotes the hypotenuse of a right-angled triangle where the given numbers are the perpendicular sides. This is a clear pattern of Pythagorean triplets. 7^2 + 24^2 = 49 + 576 = 625 = 25^2. 12^2 + 16^2 = 144 + 256 = 400 = 20^2.

Applying the exact same logic to 16 and 63: 16^2 + 63^2 = 256 + 3969 = 4225. Since sqrt(4225) = 65, the missing number is 65.

Train yourself to recognize common Pythagorean triplets (like 7-24-25 and multiples of 3-4-5) instantly; they are frequent hidden patterns in number logic questions.

Answer: (c).

Question details

Year

2025

Paper

CSAT

Question

Q6

Section

Logical & Analytical Reasoning

Sub-topic

Symbolic Operations

Type

Sequence & pattern

Difficulty

Hard

Source hint

Pattern recognition

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