Logical Reasoning - Number Series - Discussion

Discussion Forum : Number Series - Type 1 (Q.No. 19)
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

19.
Look at this series: 8, 6, 9, 23, 87 , ... What number should come next?
128
226
324
429
Answer: Option
Explanation:

8 x 1 - 2 = 6
6 x 2 - 3 = 9
9 x 3 - 4 = 23
23 x 4 - 5 = 87
87 x 5 - 6 = 429 ...

Discussion:
116 comments Page 5 of 12.

Uma mahi said:   6 years ago
How to find out this given series?

Gunjan said:   6 years ago
This is very easy to solve. Those who are basic learners in reasoning can easily solve it.

Jitumani Bhagabati said:   7 years ago
8 * 1 - 2 = 6
6 * 2 - 3 = 9
9 * 3 - 4 = 23
23 * 4 - 5 = 87
87 * 5 - 6 = 429.

David Jp said:   7 years ago
@ALL.

As per my knowledge, this will go like.
a will start from 1 and increase to 1 in next , b start from 2 and increase 1.
8 x a - b = 6,
6 x (a++) - (b++),
9 x (a++) - (b++),
23 x (a++) - (b++),
87 x (a++) - (b++).

Sayera said:   7 years ago
Please explain the solution clearly.

Nirvan said:   8 years ago
A x B = AB - ( A + B ) = Y.
8 x 2 = 16 - 10 = 6,
6* 3 = 18 - 9 = 9,
9 * 4 = 36 - 13 = 23,
23* 5 = 115 - 28 = 87,
87*6 = 522 - 93 = 429.

Abhishek said:   8 years ago
Any other simple formula?

BHAGMAT TUDU said:   8 years ago
@Bala Chandu.

The answer is 14, 916, 2536, 4964.

Anil said:   9 years ago
@All.

This question was asked in 2011 FSO exam.

Aloj said:   9 years ago
8 * 1 = 8 - 2.
6 * 2 = 12 - 3.
9 * 3 = 27 - 4.
23 * 4 = 92 - 5.
87 * 5 = 435 - 6.
429 answer.


Post your comments here:

Your comments will be displayed after verification.