Sequence,patterns and orders

Number Theory Level pending

In the following question, the numbers are arranged in a particular order or pattern. Choose the missing number from the given alternatives. 3 , 9 , 17 , 27 , ? ? 3, 9, 17, 27, ? ?

30 37 33 39

Ankit Vijay by Ankit Vijay , 22, India

This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try refreshing the page, (b) enabling javascript if it is disabled on your browser and, finally, (c) loading the non-javascript version of this page . We're sorry about the hassle.

6 solutions

Ankit Vijay
Jun 13, 2014

3 + 6 = 9

9 + 8 = 17

17 + 10 = 27

27 + 12 = 39

1 Helpful 0 Interesting 0 Brilliant 0 Confused

nice one! bro

Agustin Peñalosa Jr. - 6 years, 11 months ago
Nabil Jesús
Aug 1, 2014

A ( 1 ) = 3 , A ( i ) = ( i − 1 ) + A ( i − 1 ) + ( 3 + i ) 1 + 3 + 5 = 9 ⇒ i = 2 , A ( i ) = 9 2 + 9 + 6 = 17 ⇒ i = 3 , A ( i ) = 17 3 + 17 + 7 = 27 ⇒ i = 4 , A ( i ) = 27 4 + 27 + 8 = 39 ⇒ i = 5 , A ( I ) = 39 A(1)=3,\quad A(i)=(i-1)+A(i-1)+(3+i)\\ 1+3+5=9\quad \quad \quad \Rightarrow \quad i=2,\quad A(i)=9\\ 2+9+6=17\quad \quad \Rightarrow \quad i=3,\quad A(i)=17\\ 3+17+7=27\quad \quad \Rightarrow \quad i=4,\quad A(i)=27\\ 4+27+8=39\quad \quad \Rightarrow \quad i=5,\quad A(I)=39 .

0 Helpful 0 Interesting 0 Brilliant 0 Confused
Renuka Iyer
Jun 19, 2014

3 + 6 = 9 9 + 8 = 17 17 + 10 = 27 27 + 12 = 39

Answer is "39"

0 Helpful 0 Interesting 0 Brilliant 0 Confused
Anjna Anilkumar
Jun 17, 2014

the difference between the 3 and 9 is 6 and the difference between the 9 and 17 is 8 and the difference between the 17 and 27 is 10 . so the difference between the 6, 8 and 10 is 2 so add the 2 with 10 = 12 so the answer is 27 + 12 = 39

0 Helpful 0 Interesting 0 Brilliant 0 Confused
Henrique Ribeiro
Jun 16, 2014

27 - 17 = 10. 17 - 9 = 8. 9 - 3 = 6. The logic is 6, 8, 10. The next will be 12. Then, 27 + 12 = 39.

0 Helpful 0 Interesting 0 Brilliant 0 Confused
Ahmed Salah
Jun 14, 2014

6,8,10,12,etc....

0 Helpful 0 Interesting 0 Brilliant 0 Confused

0 pending reports

×

Problem Loading...

Note Loading...

Set Loading...