Logical Reasoning - Number Series - Discussion
Discussion Forum : Number Series - Type 1 (Q.No. 1)
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
1.
Look at this series: 2, 1, (1/2), (1/4), ... What number should come next?
Answer: Option
Explanation:
This is a simple division series; each number is one-half of the previous number.
In other terms to say, the number is divided by 2 successively to get the next result.
4/2 = 2 2/2 = 1 1/2 = 1/2 (1/2)/2 = 1/4 (1/4)/2 = 1/8 and so on.
Discussion:
182 comments Page 3 of 19.
Lisa Price said:
1 decade ago
I need help finding the next number in the series to:
1. 18,81,27,36,63?
2. 1/64,1/32,1/16,1/8,1/4,1/2?
3. 36,37,39,42,46,51?
4. 8,4,2,1,.5,.25,.25?
5. 2,4,6,5,7,9,8?
6. 154,77,81,78,39,43,40?
7. 1/2,1/4,1/3,1/6,1/5?
8. 2,3,4,8,9,10,20,21,22?
9. 2,5,14,41,122?
10. 15,18,54,57,171?
11. 18,81,27,72,36,63?
12. 1/64,1/32,1/16,1/8,1/4,1/2?
13. 36,37,39,42,46,51?
14. 2,4,6,5,7,9,8?
15. 154,77,81,78,39,43,40?
1. 18,81,27,36,63?
2. 1/64,1/32,1/16,1/8,1/4,1/2?
3. 36,37,39,42,46,51?
4. 8,4,2,1,.5,.25,.25?
5. 2,4,6,5,7,9,8?
6. 154,77,81,78,39,43,40?
7. 1/2,1/4,1/3,1/6,1/5?
8. 2,3,4,8,9,10,20,21,22?
9. 2,5,14,41,122?
10. 15,18,54,57,171?
11. 18,81,27,72,36,63?
12. 1/64,1/32,1/16,1/8,1/4,1/2?
13. 36,37,39,42,46,51?
14. 2,4,6,5,7,9,8?
15. 154,77,81,78,39,43,40?
Vinod said:
1 decade ago
Hey its very easy see.
2^1, 2^0, 2^-1, 2^-2, 2^-3
2^1=2
2^0=1
2^-1=(1/2)
2^-2=(1/4)
2^-3=(1/8)
2^1, 2^0, 2^-1, 2^-2, 2^-3
2^1=2
2^0=1
2^-1=(1/2)
2^-2=(1/4)
2^-3=(1/8)
Avinash goyal said:
1 decade ago
Every time the denominator get doubled and the numerator rest with 1.
Trinadh.K said:
1 decade ago
@Lisa Price:
1. 18, 81, 27, 36, 63, 45, 54, 45....
2. 1/64, 1/32, 1/16, 1/8, 1/4, 1/2, 1, 2, 4... (you just multiply with 2).
3. 36, 37, 39, 42, 46, 51, 57, 64.. (+1 +2 +3 +4 +5 +6 +7).
1. 18, 81, 27, 36, 63, 45, 54, 45....
2. 1/64, 1/32, 1/16, 1/8, 1/4, 1/2, 1, 2, 4... (you just multiply with 2).
3. 36, 37, 39, 42, 46, 51, 57, 64.. (+1 +2 +3 +4 +5 +6 +7).
Sravan handsome said:
1 decade ago
How we will expect first number is 4?
Sagar said:
1 decade ago
I want to say that this series consist of successive powers of 2.
Haris said:
1 decade ago
Nice but how can we expect this logic as first number is 4.
Himanshu said:
1 decade ago
Just take a half of the number series.
1, 2 ...then,
2. 1/2 means 2/2 = 1;
3. 1/2 means 1/2/2 = 0.5/2 ( we can assume 1/2 as 0.5) = 1/4 and so on...
1, 2 ...then,
2. 1/2 means 2/2 = 1;
3. 1/2 means 1/2/2 = 0.5/2 ( we can assume 1/2 as 0.5) = 1/4 and so on...
Naveen said:
1 decade ago
5. 2, 4, 6, 5, 7, 9, 8, ?
Just add 2 up to 3 numbers and then subtract 1 from the third number.
2+2 = 4.
4+2= 6.
6-1 = 5.
5+2 = 7.
7+2 = 9.
9-1 = 8.
8+2 = 10.
10+2 = 12.
Just add 2 up to 3 numbers and then subtract 1 from the third number.
2+2 = 4.
4+2= 6.
6-1 = 5.
5+2 = 7.
7+2 = 9.
9-1 = 8.
8+2 = 10.
10+2 = 12.
Surbhi agrawal said:
1 decade ago
Look at this:
2 - 1 = 1.
1 - 1/2 = 1/2.
1/2 - 1/4 = 1/4 .
Now,
1/4 - 1/8 = 1/8.
So answer is 1/8.
2 - 1 = 1.
1 - 1/2 = 1/2.
1/2 - 1/4 = 1/4 .
Now,
1/4 - 1/8 = 1/8.
So answer is 1/8.
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