Question

Find the missing number 7,3,2,4,9,6,2,1,5,69,91,?

Answer 1

$Given \: numbers :$

7 , 3 , 2

4 , 9 , 6

2 , 1 , 5

69, 91 ,?

/* Observe the sequence ,we find following pattern */

$i) 7^{2} + 4^{2} + 2^{2} \: \blue { (First \: column )}$

$= 49 + 16 + 4$

$= 69$

$ii) 3^{2} + 9^{2} + 1^{2} \: \blue { (Second \: column )}$

$= 9 + 81 + 1$

$= 91$

$iii) 2^{2} + 6^{2} + 5^{2} \: \blue { (Third\: column )}$

$= 4 + 36 + 25$

$\red{ = 65}$

Therefore.,

$\red{ Missing \: number } \green { = 65 }$

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