What is X? 24 81 63 26 412 8 25 X

M4maths Previous Puzzles

19 Oct 2015 Sequence

What is X?
24 81 63 26 412 8 25 X

OPtion

1) 3
2) 4
3) 5
4) 6
5) 8
6) 7
7) 2
8) 1
9) 9
10)None of these

Solution

The series is spaced incorrectly. When the spacing is correct it becomes:
2 4 8 16 32 64 128 256,

which is an obvious doubling-up series.

Option 4) 6

Correct Option: 4 Best Solution (7)

Chandrajeet Yadav   9 years AGO

24 81 63 26 412 8 25 X

After omitting the space between numbers we get
24816326412825X

Here we can see that series is in GP with common ratio = 2
So after arranging accordingly we get
2 4 8 16 32 64 128 25X

So the last term (25X) must be 128*2 = 256
And now we can see easily that X = 6
Now series become as follows-
24 81 63 26 412 8 25 6

Option (4

Like? Yes (10) | No (1)  

kriti kankariya   9 years AGO

24 81 63 26 412 8 25 = 2 4 8 16 32 64 128 256
multiplying by 2 at every step
so ans is 6

Like? Yes (3) | No   

NAVEEN KUMAR   9 years AGO

2..2*2(4)--4*2(8)8*2(16)16*2(32)32*2(64)64*2(128)128*2(256)......6(ans)

Like? Yes (3) | No   

MRITUNJAY   9 years AGO

2 4 8 16 32 64 128 256

so 6 is the right answer

Like? Yes (1) | No   

RAHUL KUMAR   9 years AGO

2 4 8 16 32 64 128 256
so the X is 6
option (4) is right.

Like? Yes (1) | No   

Ann Theressa   9 years AGO

The sequence is 2 4 8 16 32 64 128 256 ( 2^1 2^2 2^3 2^4 2^5 .... )

Like? Yes (1) | No   

Nandkishor jaiswal   9 years AGO

if we adjust each term then we it in the power series of 2 that is
2 4 8 16 32 64 128 256
so missing term is 6

Like? Yes (1) | No