# Sequence of numbers

I can not figure this sequence out. I have tried looking at the differences or differences of differences.

Fill in the dots:

83 80 84 83 88 95 ...

Choose one of the following answers: 87 95 91 83

Can somebody help me?

Step 1 :

Remove 80 from all numbers, so you have : 0 3 4 3 8 15

Step2:

Now index the numbers : 1 2 3 4 5 6 ... 0 3 4 3 8 15

Step 3:

Sum the numbers with indexes :

Sequence:

1 5 7 7 13 21

Result:

You can see that this is a growing sequence, so I'd say 95 is next to keep it growing. 95 -> 15 at index 7 -> 22

• Why is step 1 needed? – jafe Jul 25 '18 at 12:55
• just to make it easier to represent the numbers, def not 'needed' :D – toto Jul 25 '18 at 12:56
• Sorry I mixed two numbers up. I corrected it. – Dennispuz Jul 25 '18 at 12:59
• @user3757341 demn! :'( – toto Jul 25 '18 at 13:01
• @toto: this is the correct sequence :). – Dennispuz Jul 25 '18 at 13:03

87. Probably not the correct answer and not a very logical explanation, but here goes nonetheless:

Explanation 1: Adding the digits together gives us the sequence: 11 8 12 11 16 14. The terms are going down and up alternately. Next term must go up. From the answers, only 8+7=15 is greater than 14. Hence, 87 is the answer.

Explanation 2: Reversing the digits gives us the sequence: 38 08 48 38 88 59. The terms are going down and up alternately. Next term must go up. From the answers, only 87 -> 78 is greater than 59. Hence, 87 is the answer.

• So I thought this: 84-83 =1, 88-84 =4 so: 88+7 = 95? – Dennispuz Jul 25 '18 at 13:24

Maybe the rule is as simple (and stupid) as

83 every 3 numbers. Which would make the answer 83. This might not be the answer that the question is looking for, but it applies and thus is correct nonetheless.