Logical Reasoning - Number Series - Discussion
Discussion Forum : Number Series - Type 1 (Q.No. 8)
Directions to Solve
In each series, look for the degree and direction of change between the numbers. In other words, do the numbers increase or decrease, and by how much
8.
Look at this series: 3, 4, 7, 8, 11, 12, ... What number should come next?
Answer: Option
Explanation:
This alternating addition series begins with 3; then 1 is added to give 4; then 3 is added to give 7; then 1 is added, and so on.
Discussion:
38 comments Page 1 of 4.
Rajesh Pradhan said:
1 decade ago
This is a very good question.
There is an alternative method for solving this problem.
IE, digit at even & odd places are changes simultaneously.
IE, digit at odd place:- 3+4=7, 7+4=11, 11+4=15 and so on.
& digit at even place:- 4+4=8, 8+4=12 and so on.
Thus here, the answer is 11+4=15.
There is an alternative method for solving this problem.
IE, digit at even & odd places are changes simultaneously.
IE, digit at odd place:- 3+4=7, 7+4=11, 11+4=15 and so on.
& digit at even place:- 4+4=8, 8+4=12 and so on.
Thus here, the answer is 11+4=15.
Tukaram Patil said:
1 decade ago
After 3, 4 this alternative 2 nos. are missing i.e(5 & 6).
After 7, 8 this alternative 2 nos. are missing i.e(9 & 10).
After 11, 12 this alternative 2 nos. should miss i.e(13 & 14).
So D ans is 15.
After 7, 8 this alternative 2 nos. are missing i.e(9 & 10).
After 11, 12 this alternative 2 nos. should miss i.e(13 & 14).
So D ans is 15.
Sunita S. said:
1 decade ago
after 3, 4 this alternative 2 nos. r missing i.e(5 & 6)
after 7, 8 this alternative 2 nos. r missing i.e(9 & 10)
after 11, 12 this alternative 2 nos. should miss i.e(13 & 14)
so d ans is 15.
after 7, 8 this alternative 2 nos. r missing i.e(9 & 10)
after 11, 12 this alternative 2 nos. should miss i.e(13 & 14)
so d ans is 15.
Sathish Kumar said:
9 years ago
There is a simple logic.
After 3 and 4 it is 5 and 6 (5 and 6 not shown).
Again after 7, 8 it is 9, 10 (9, 10 not shown).
So 11 and 12 probably it would be 13, 14.
And so the next number is 15.
After 3 and 4 it is 5 and 6 (5 and 6 not shown).
Again after 7, 8 it is 9, 10 (9, 10 not shown).
So 11 and 12 probably it would be 13, 14.
And so the next number is 15.
Kunal said:
7 years ago
Take alternate series 4,8,12.
Now .
4*2=8
4*3=12
4*4=16.
From here you can see every previous digit is 1 less then current digit according to the whole series.
So, the answer is 15.
Now .
4*2=8
4*3=12
4*4=16.
From here you can see every previous digit is 1 less then current digit according to the whole series.
So, the answer is 15.
(1)
Sanju reddy said:
1 decade ago
It can also be done in this way.
4-3=1
7-4=3
8-7=1
11-8=3
12-11=1
15-12=3
Therefore, the difference b/w the two consecutive no's is in the form 1,3,1,3,1 and so on.
4-3=1
7-4=3
8-7=1
11-8=3
12-11=1
15-12=3
Therefore, the difference b/w the two consecutive no's is in the form 1,3,1,3,1 and so on.
VAIBHAV said:
6 years ago
It's very easy to see.
They combine odd and even number they give alternate odd and even no.
3,4,7,8,11,12,__?
3,7,11,15 are odd.
4,8,12are even,
Ans -15.
They combine odd and even number they give alternate odd and even no.
3,4,7,8,11,12,__?
3,7,11,15 are odd.
4,8,12are even,
Ans -15.
(4)
Venkatesh Prasad said:
1 decade ago
It is a series of odd numbers.
Were the even place numbers are subtracted by 1.
3, 5, 7, 9, 11, 13, 15
(5-1) (9-1) (13-1)
3, 4, 7, 8, 11, 12, 15
Were the even place numbers are subtracted by 1.
3, 5, 7, 9, 11, 13, 15
(5-1) (9-1) (13-1)
3, 4, 7, 8, 11, 12, 15
SARTHAK said:
1 decade ago
In 3 7 & 11 difference between them is 4 on the other hand difference between 4 8 &12 is also 4. So according to this logic the answer is 16.
Rupesh Kumar Yadav said:
3 years ago
3,4 go to next 7 ,8 Till 3 different
7,8 go to next 11,12 Till 3 different
11,12 go to next 15,16 Till
so
to come 15 the answer
7,8 go to next 11,12 Till 3 different
11,12 go to next 15,16 Till
so
to come 15 the answer
(9)
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