Select the option that is related to the third number in the same way as the second number is related to the first number and the sixth number is related to the fifth number.
6:16::7:?::5:13
- A21
- B17
- C15
- D19
Solution & Step-by-step Explanation
Let us look closely at the relationship established between the numbers in the given pairs:
First pair:
6:16
The logic applied is:
(First number×3)−2=Second number
(6×3)−2=18−2=16
Third pair:
5:13
Applying the same logic:
(5×3)−2=15−2=13
Now, applying this identical logic to the middle pair (7:?):
7×3−2=21−2=19
Hence, the missing number is 19.
First pair:
6:16
The logic applied is:
(First number×3)−2=Second number
(6×3)−2=18−2=16
Third pair:
5:13
Applying the same logic:
(5×3)−2=15−2=13
Now, applying this identical logic to the middle pair (7:?):
7×3−2=21−2=19
Hence, the missing number is 19.