# Replace ? by number

This chain of numbers is making confused.Help to find the answer with explanation.

• Sorry! my mistake there was 6 in the end the solution given by @ibn-e-battota satisfies for 6 in the end. – Mateen Ahmed Dec 9 '18 at 15:50

16.

Explanation:

Moving forward ,around alternate segments in the chain , one sequence decreases by 1,2,3 and 4 each time, while the other increases by 2,3,4 and 5

• @Ibnebatoota Your solution doesn't work for the elements 10 and 9. – rhsquared Dec 9 '18 at 15:34
• Question posted have mistake there should be 6 not 9 in question. My solution satisfies 6. – Ibn-e-batoota Dec 9 '18 at 15:49