# What number follows the sequence?

I was taking a job application exam online and encountered a pattern I couldn't solve.

? 26, 13.2, 3.6, 2, 1.2, ?

What number comes next? Answer choices were:

• 7.2
• 5.4
• 6.4
• 6.8
• 7
• 6.6

I guessed 6.6 due to the pattern right of the decimal, but I couldn't see any trend left of the decimal.

What number comes next?

## 3 Answers

I believe the answer is

6.8

Reason

You start with 1.2 which is the least number and continue like this: $$(1.2*2)-0.4=2, (2*2)-0.4=3.6, (3.6*2)-0.4=6.8, (6.8*2)-0.4=13.2, (13.2*2)-0.4=26$$

• good finding, but in your case I would expect the " ?" between 13.2 and 3.6 and not at the end. – ThomasL Feb 13 at 19:26
• It might just be a "find the most fitting number"- question, disguised as a traditional number sequence – Prim3numbah Feb 13 at 21:57

Μy answer is 6

My reasoning is based on the following subtractions and additions.

 26-13.2=12.8              3.6+2+1.2+6=12.8

26-13.2-3.6=9.2           2+1.2+6=9.2

26-13.2-3.6-2=7.2         1.2+6=7.2

26-13.2-3.6-2-1.2=6         =6

26-13.2-3.6-2-1.2-6=0       =0

• That seems rather plausible. Nice find. Unfortunately I can't confirm the correct answer, but I appreciate the replies in this thread and will help me to think about it going forward. – Blaise Feb 14 at 13:28
• I don't see what is special here. It seems like you could produce the first line using any sequence of numbers (replacing 6 by the appropriate choice) After the first line, all you are doing is subtracting the same number from both equations. – hexomino Feb 15 at 14:22
• I had to work with the given numbers. – Vassilis Parassidis Feb 15 at 17:54

Maybe this pattern is too weird to be the actual answer, nevertheless it's a pattern.

The answer would be

7.2

Reason

If you sum the digits of the numbers, you get the pattern:
Even Odd Odd Even Odd
So the next should give an odd sum of digits

Then you notice that all the three "Odd" in the sequence have decimals and if you multiply the integer part by the decimal you obtain a number that is divisible by 2 just once (not divisible by 4)

7.2 is the only answer with a decimal part, whose sum of digits is odd and product of integer and decimal part is divisible by 2 only once.