Select the option that is related to the fifth number in the same way as the second number is related to the first number and the fourth number is related to the third number.
15: 4:: 21: 6:: 42:?
Show answer & explanation
Correct answer: C
Explanation
The correct answer is Option 3 i.e. 13.
The logic used here is:
15: 4
4 × 3 + 3 = 12 + 3 = 15
21: 6
6 × 3 + 3 = 18 + 3 = 21
Similarly,
42:?
a × 3 + 3 = 42
a × 3 = 39
a = 13
Hence, 13 is the correct answer.