Logical Reasoning - Number Series - Discussion

Discussion Forum : Number Series - Type 1 (Q.No. 12)
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

12.
Look at this series: 14, 28, 20, 40, 32, 64, ... What number should come next?
52
56
96
128
Answer: Option
Explanation:
This is an alternating multiplication and subtracting series: First, multiply by 2 and then subtract 8.
Discussion:
86 comments Page 9 of 9.

Prasanth said:   1 decade ago
Why can't we say the Answer D.

As it was Multiplied by 2 with each number and with last 64*2 can get 128.

Amit said:   1 decade ago
Why we subtract? Its simple multiplication in sequence.
14*2 = 28.
20*2 = 40.
32*2 = 64.
64*2 = 128.

Answer 128.

Pawan sharma said:   1 decade ago
14*2 = 28,28-8 = 20;
20*2 = 40,40-8 = 32;
32*2 = 64,64-8 = 56;

Answer is 56.

Sonam said:   1 decade ago
14*2 = 28.
28-8 = 20.
20*2 = 40.
40-8 = 32.
32*2 = 64.
64-8 = 56 easy method.

Anu said:   1 decade ago
The 2 nos as one set 14, 28 , 20, 40, 32, 64..

So it can be divided as (7x2),(7x4),(10x2),(10x4),(16x2),(16x4)..

So now 7, 10, 16 fall a line.
And

7+3 = 10
10+6 (3x2)=16
16+12(6x2)=28

(or)  

7+3 (3x1) = 10
10+6(3x2) =16
16+9(3x3) =25

So the series may be either,

7, 10, 16, 28
or
7, 10, 16, 25

If we take the first series then we will get 28x2 = 56.

If we take the next series then we will get 25x2 = 50.

Both answers are correct but as we have only 56 as option here 56 is the right answer.

Sayantika said:   1 decade ago
14+6=20
20+(6*2)=32
32+(12*2)=56

Like this:

28+12=40
40+(12*2)=64
64+(24*2)=112


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