UPSC CSE 2025 · PYQ · Number Series / Pattern Recognition · easy
If 7 * 24 = 25 and 12 * 16 = 20, then what is 16 * 63 equal to ?
A.70
B.66
C.65✓ Correct
D.64
Explanation
The pattern is a*b = √(a²+b²), i.e., the hypotenuse of a right triangle. Check: √(7²+24²) = √(49+576) = √625 = 25 ✓; √(12²+16²) = √(144+256) = √400 = 20 ✓. Apply the rule: 16*63 = √(16²+63²) = √(256+3969) = √4225 = 65. So the answer is 65.
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