GATE2014 EC-3: GA-6

Question

Find the next term in the sequence: $7G, 11K, 13M$, _________.

• A. $15Q$
• B. $17Q$ 
• C. $15P$
• D. $17P$

Comments

My approach was wrong but it just worked like adding 4 to 7G = 11K and adding 2 to 11K which is equal to 13M.And again 4 to 13M then just got 17Q.

Answer 1

7G - G is the 7th alphabet
11K - K is the 11th alphabet
13M - M is the 13th alphabet

15th alphabet is O
17th alphabet is Q
Therefore A,C,D eliminated
Also, 7,11,13 are prime numbers, next prime in the sequence would be 17

Answer Option B) 17Q

Answer 2

one good way to solve these questions is write down the letters and number them .It will hardly take 1.5 min in the exam A B C D E F G H I J K L M N O P Q R S T U V W X Y Z 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 now the question says 7G 11K 13M ..notice the pattern here ..the letters have their corresponding numbers so the next term is 17Q.. SO answer is B

Comments

Even now also following the same method

Answer 3

In the given series the numbers are the prime numbers;$7,11,13,17..$

$7\xrightarrow{+4}11\xrightarrow{+2}13\xrightarrow{+4}17$

in the same way

$G\xrightarrow{+4}K\xrightarrow{+2}M\xrightarrow{+4}Q$

So the next term is $17Q$. Option $(B)$ is correct.