Question

Choose the most appropriate option to replace (?).
121, 144, 289, 324, 529, 576, ?

• A. 961
• B. 841
• C. 900
• D. 729
• E. None of the above

Answer 1

The correct option is D 729

11 $\times$ 11 = 121
12 $\times$ 12 = 144
Difference = 17 - 12 = 5
17 $\times$ 17 = 289
18 $\times$ 18 = 324
Difference = 23 - 18 = 5
23 $\times$ 23 = 529
24 $\times$ 24 = 576
Likewise,
? - 24 = 5
? = 29
Hence, 29 $\times$ 29 = 729