Directions: Pick the correct options from the given alternatives 20 : 39 :: 25 : ?
Show answer & explanation
Correct answer: C
Explanation
20 : 39 :: 25 : ?
Just as
20 : 39
20 × 2 − 1 = 40 − 1 = 39
That is, the rule:
n × 2 − 1
Similarly,
25 : ?
25 × 2 − 1
= 50 − 1
? = 49
Correct answer: 3) 49