Select the option that is related to the third term in the same way as the second term is related to the first term and the sixth term is related to the fifth term.
29 : 61 :: 47 : ? :: 15 : 33

To find the missing term in the analogy, let us analyze the relationship between the numbers in the given pairs:
First pair: 29 : 61
Third pair: 15 : 33

Let us check the mathematical relation in the third pair: 15 : 33
If we multiply the first number by 2 and add 3, we get:
$15\times 2+3=30+3=33$

Let us verify if this same logic applies to the first pair: 29 : 61
If we multiply 29 by 2 and add 3, we get:
$29\times 2+3=58+3=61$
Since the logic holds true for both pairs, we can apply the same rule to the second pair: 47 : ?

Applying the rule to 47:
$47\times 2+3=94+3=97$

Therefore, the missing term is 97, which corresponds to the correct option.