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:
39 comments Page 4 of 4.
Rajesh Pradhan said:
2 decades 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.
Rahul said:
1 decade ago
3+1 = 4.
4+3 = 7.
7+1 = 8.
.
.
12+3 = 15.
Answer is 15.
4+3 = 7.
7+1 = 8.
.
.
12+3 = 15.
Answer is 15.
Kavi kanyal said:
1 decade ago
2*1+1 = 3.
2*2 = 4.
2*3+1 = 7.
2*4 = 8.
2*5+1 = 11.
2*6 = 12.
2*7+1 = 15.
2*2 = 4.
2*3+1 = 7.
2*4 = 8.
2*5+1 = 11.
2*6 = 12.
2*7+1 = 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.
Mahendra Thakur said:
1 decade ago
See odd numbers and add all odd numbers by 4 like.
3+4=7.
7+4=11.
11+4=15.
Answer is 15.
3+4=7.
7+4=11.
11+4=15.
Answer is 15.
Shree said:
1 decade ago
3, 4, 7|8, 11, 12.
3-7=4.
8-12=4.
Since 15-11=4.
3-7=4.
8-12=4.
Since 15-11=4.
Roshan Roy said:
10 years ago
The formula is +1 then +3 :
3+1=4.
4+3=7.
7+1=8.
8+3=11.
11+1=12.
Since 12+3=15.
3+1=4.
4+3=7.
7+1=8.
8+3=11.
11+1=12.
Since 12+3=15.
Sagar said:
10 years ago
Can we do it like this,
3-4 = -1
4-7= -3
7-8 = -1
8-11 = -3
11-12 = -1
12-15 = -3
3-4 = -1
4-7= -3
7-8 = -1
8-11 = -3
11-12 = -1
12-15 = -3
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.
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