# An X-Mensa dq question

Which of the numbers should fill in the ?.

4, 3, 4, 7, 0, 45, 7, 15, 64, 0, 1111, 55, 5, 5, 0, 20, 32, 1, ?

a) 2

b) 0

c) 20

d) 1

Hints:

1.

There is a reason why the number-sequence tag was omitted.

Where to begin... How can the first 4 numbers be relevant to the seasonal tag?

What are 4 basic math operations?

Step 1:

Taking 0 as the separator of the sequence to get four groups of four numbers each, and concatenating these four numbers into two, we get:
(43, 47), (457, 1564), (111155, 55), (2032, 1?)

Step 2:

We can then place three of the four basic mathematical operators between the complete pairs of numbers to get a seasonal result:
43 × 47 = 2021, 457 + 1564 = 2021, 111155 ÷ 55 = 2021

Step 3:

So ? is equal to 1, as when the remaining mathematical operator is used on the resultant pair of numbers, we get:
2032 - 11 = 2021

Happy New Year!

• Nice one, I didn't expect it to take so long! Also please put some spoiler tags >!. Commented Jan 6, 2021 at 14:17