40 is related to 53 following a certain logic. Following the same logic, 8 is related to 13. To which of the following numbers is 68 related, following the same logic?
(NOTE: Operations should be performed on the whole numbers, without breaking down the numbers into their constituent digits. E.g. 13 – Operations on 13, such as adding /deleting /multiplying, etc., to 13 can be performed. Breaking down 13 into 1 and 3 and then performing mathematical operations on 1 and 3 is not allowed.)
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. 85
40 is related to 53 → [{√(40 - 4)} + 1]2 + 4 = {(√36) + 1}2 + 4 = 49 + 4 = 53
8 is related to 13 → [{√(8 - 4)} + 1]2 + 4 = {(√4) + 1}2 + 4 = 9 + 4 = 13
Similarly, 68 is related: → [{√(68 - 4)} + 1]2 + 4 = {(√64) + 1}2 + 4 = 81 + 4 = 85