Logical Reasoning - Number Series - Discussion

Discussion Forum : Number Series - Type 2 (Q.No. 7)
Directions to Solve
Look carefully for the pattern, and then choose which pair of numbers comes next.

7.
17 17 34 20 20 31 23
26 23
34 20
23 33
27 28
23 28
Answer: Option
Explanation:
This is an alternating subtraction series with repetition. There are two different patterns here. In the first, a number repeats itself; then 3 is added to that number to arrive at the next number, which also repeats. This gives the series 17, 17, 20, 20, 23, and so on. Every third number follows a second pattern, in which 3 is subtracted from each number to arrive at the next: 34, 31, 28.
Discussion:
33 comments Page 1 of 4.

Pranjal Deori said:   4 years ago
@All.

According to me, the solution is;

7 17(34) 20 20 (31) 23 23 (28)

(34-3=31).
(31-3 =28).
(32)

Ali said:   5 years ago
17 17 34 20 20 31 23:

(17 17) (34) (20 20) (31) (23).
1:17 20 and 23.
2:34 and 31.

Two different series . In 1:(+3) and 2:(-3);
So the answer =23 28.
(8)

Khyati Singh said:   3 years ago
Thanks all for explaining the answer.
(6)

SHUBHAM KUMAR said:   3 years ago
17 17 34 20 20 31 23.

17+(0+17)+(17+17).
20+(0+20)+{20+11(17-6)}.
23+(0+23)+{23+5(11-6)}.


And the order is; 17 17 34 20 20 31 23 23 28.
(5)

Guri Singh said:   5 months ago
17 + 3 = 20,
20 - 3 = 17,
31 + 3 = 34,
34 - 3 = 31,
23 + 3 = 26,
26 - 3 = 23.
26.23 is the answer.
(3)

Nithin said:   8 years ago
Nice explanation @Rajanna.
(3)

Hely said:   7 years ago
The one pattern i used to solve this series is:

17 + 17 = 34 (17=prime number).
34 - 14 = 20 (17-3=14).
20 + 11 = 31 (11=prime number) (skipping a prime number after 17).
31 - 8 = 23 (11-3=8).
23 + 5 = 28 (5=prime number) (skipping a prime number after 11).
(3)

Roopa said:   9 years ago
In simple,

(17 17) 34 (20 20 ) 31 (23 ?)

Here,
17 + 3 = 20.
20 + 3 = (23).
And 34 - 31 = 3.
31 - (28) = 3.

Ans are in brakets.
(2)

Shanmukh Adari said:   7 years ago
Well said @Rajanna.
(2)

Saurabh said:   1 decade ago
17
17+17=34 nothing is subtracted here
20
20+20=40, 9 is subtracted here =31
23
23+23=46,18 is subtracted here = 28
so option e is correct
(1)


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