Aptitude - Odd Man Out and Series - Discussion
Discussion Forum : Odd Man Out and Series - Missing No. (Q.No. 12)
Directions to Solve
Insert the missing number.
12.
15, 31, 63, 127, 255, (....)
Answer: Option
Explanation:
Each number is double the preceding one plus 1.
So, the next number is (255 x 2) + 1 = 511.
Discussion:
6 comments Page 1 of 1.
Mukesh said:
9 years ago
15 x 2 = 30 + 1 = 31,
31 x 2 = 62 + 1 = 63,
63 x 2 = 126 + 1 = 127,
So, 255 x 2 = 510 + 1 = 511.
31 x 2 = 62 + 1 = 63,
63 x 2 = 126 + 1 = 127,
So, 255 x 2 = 510 + 1 = 511.
(1)
Ardyula dattatreya sarma said:
1 decade ago
Another way to answer it
the difference between number is increased double
15+16=31
31+32=63
63+64=127
127+128=255
255+256=511
the difference between number is increased double
15+16=31
31+32=63
63+64=127
127+128=255
255+256=511
Gowtham Mx said:
1 decade ago
My view of the problem:
(2*2*2*2)-1 = 15.
(2 to the power 5)-1 = 31.
And so on, finally,
(2 to the power 9)-1 = 512-1 = 511.
(2*2*2*2)-1 = 15.
(2 to the power 5)-1 = 31.
And so on, finally,
(2 to the power 9)-1 = 512-1 = 511.
Yogesh said:
1 decade ago
Previous number "255" ending with 5.
Comparing similar characteristics with the numbers in series.
We can observe that "15" ending with 5 and has the next number "31" By this we can predict that the next number of "255" must end with "1"
ANSWER: 511.
Comparing similar characteristics with the numbers in series.
We can observe that "15" ending with 5 and has the next number "31" By this we can predict that the next number of "255" must end with "1"
ANSWER: 511.
Eamon said:
9 years ago
#1 = 1
#2 = 1 + 1 + 1 = 3
#3 = 3 + 3 + 1 = 7
#4 = 7 + 7 + 1 = 15
#5 = 15 + 15 + 1 = 31
#6 = 31 + 31 + 1 = 63
#7 = 63 + 63 + 1 = 127
#8 = 127 + 127 + 1 = 255
#9 = 255 + 255 + 1 = 511.
#2 = 1 + 1 + 1 = 3
#3 = 3 + 3 + 1 = 7
#4 = 7 + 7 + 1 = 15
#5 = 15 + 15 + 1 = 31
#6 = 31 + 31 + 1 = 63
#7 = 63 + 63 + 1 = 127
#8 = 127 + 127 + 1 = 255
#9 = 255 + 255 + 1 = 511.
Nitish Kumar said:
9 months ago
Anyone, solve the answer in detail to understand it easily?
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