Find missing number ( ) 1, 3, 3, 6, 7, 9, __ ,12, 21
Answers
This is how I am guessing it’s the answer -
Alternatively from the second digit if u notice, it is 3,6,9,12 all of which are multiples of 3 increasingly. So just leave that set.
Now look that sequence alternatively from the first digit - 1,3,7,_,21
Here they r all odd numbers. First1, then 3 but you seee 5 is missing, they put 7 instead . So here they skipped 1 odd number. Next, let’s assume, they skip 2 odd numbers, so 9 and 11 will be skipped. So let’s asssume 13 comes. Next, 3 odd numbers shud be skipped that is,15,17 and 19. So 21 must come and if u see in the question, 21 is there. So this sequence might be right, this is how I am guessing 13 is the answer.
Hope this helps ya
Given:
A series of numbers 1, 3, 3, 6, 7, 9, __, 12, 21.
To Find:
The missing number in the above blank is?
Solution:
The given problem can be solved by developing a common logic between every term.
1. The given sequence is 1, 3, 3, 6, 7, 9, __, 12, 21.
2. Consider the even positioned terms of the series,
=> Even positioned terms are 3, 6, 9, 12, 21.
=> The even positioned terms follow a pattern of multiples of 3.
3. Consider the oddly positioned terms of the series,
=> Odd positioned terms = 1, 3, 7, __, 21.
=> A gap of 2, 4, is observed in the second and third terms. Hence a gap of 6 will be observed for the third term and a gap of 8 will be observed in the 4th term.
=> Third term = 7 + 6 = 13.
=> Fourth term = 13 + 8 = 21.
=> The missing number is 13.
Therefore, the missing number is 13.