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:
85 comments Page 6 of 9.

Yash said:   10 years ago
14+6=20.
20+8=28.
28+4=32.

32+8=40.
40+8=48.
48+8=56.
56+8=64.

Chalin said:   1 decade ago
14+14=28.

And then subtract 28-8=20.

20+20=40.

And subtract.

40-8=32.

And add above number.

32+32=64.

And now subtract.

64-8=56.

You get the answer 56.

Gideon Brian said:   1 decade ago
I have this question: A series has 17 numbers, if the second is 3, what is the fast number?

Suman sundar said:   1 decade ago
14*(2)28 - (8)20*(2)40 - (8)32*(2)64 - (8)56.

Suraj said:   1 decade ago
14, 28(14*2), 20(14+6), 40(28+12), 32(20+12), 64(40+24), 56(32+24) + (24*2)112

Rs said:   1 decade ago
Look at the alternate series 14, 28, 20, 40, 32, 64

14-20 = -6 28-40 = 12.
20-32 = -12(Double of above) 40-64 = 24(Double of above).

So,
32-? =Double of above i.e. 12+12 = 24.

Answer is 32+24 = 56.

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.


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