Question

Fill in the missing number:
11, 10, ?, 100, 1001, 1000, 1001

• A. 110
• B. 111
• C. 101
• D. 100
• E. None of the above

Answer 1

The correct option is C 101

1st, 3rd, 5th, 7th, terms are 1: 11, ?, 1001 10001 and 2nd, 4th, 6th, terms are
2: 10, 100, 1000
In 1:
(1) at the 1st place, there no zeros between 1's
(2) at the 3rd place, there are 2 zeros between 1's
(3) at the 4th place, there are 3 zeros between 1's
$\therefore$ According to this pattern there should be 1 zero between 1's at 2nd place
$\therefore$ ? be 101.