Question

Consider the following and find the values of ? in 49 : 21 :: 169 : ?
(A) 26
(B) 39
(C) 42
(D) 13

Answer 1

Hint: Here in this question we have been asked to find the next term in the given pattern 49 : 21 :: 169 : ___ . From the basic concepts of logical reasoning we know that these types of sequences follow a specific pattern in themselves; they have a unique relationship between the terms. We will depict the relationship between the terms in this case and then find the next or missing term.

Complete step by step answer:
Now considering from the question we have been asked to find the next term in the given pattern 49 : 21 :: 169 : ___ .
From the basic concepts of logical reasoning we know that these types of sequences follow a specific pattern in themselves; they have a unique relationship between the terms.
Firstly let us see how simply we can express the first term 49 instantaneously we will get an idea to express it as the square of 7.
Now we will see the same with the second term 21 we will say that it is the product of 3 and 7.
Now we can say that the next term 169 is the square of 13 by observing it.
Now we can say that the next terms of the given sequence will also be having the same relationship as the first two terms. That is, the next or missing term will be the product of 13 and 3 .
Since the first set of terms the first term is the square of 7 and in the second set the first term is the square of 13 and similarly the second term in the first set is the product of 7 and 3 and similarly the second term in the second set will be the product of 13 and 3.
Therefore we can conclude that the next or missing term in given pattern 49 : 21 : : 169 : _____ is 39.

So, the correct answer is “Option B”.

Note: While answering questions of this type we should carefully observe the pattern followed, mistakes are very rarely possible but sometimes the answer or pattern we cannot identify because it does not strike our mind immediately so we should practice more questions of this type in order to perform them well.