A number series is given with one term missing, find it. 21, 25, 33, 49, 81,?
The pattern is 21+ 4, 25+ 8, 33+ 16, 49+ 32,.... i.e. + 2*2, + 2*2*2, + 2*2*2*2, + 2*2*2*2*2,... .'. Missing number = 81 + 2*2*2*2*2*2 = 81 + 64 = 145.
145
The difference between consecutive numbers in the sequence is an increasing power of 2 , i.e., 2^2, 2^3, 2^4, 2^5, 2^6, etc.
Can you complete the table series puzzle by replacing the ?? with the correct number?
81 36 144 ?? 25 16 64 100 49
