Select the option which is related to fifth number in the same way as second number is related to first number and fourth number is related to third number.
(Note: Numbers must be operated on whole numbers, without dividing them into their constituent digits. For example on 13 - 13 arithmetic operations like addition/subtraction/multiplication etc. can be done in 13. Dividing 13 into 1 and 3 and then doing arithmetic operations on 1 and 3 is not allowed.)
20 : 30 :: 42 : 56 :: 72 : ?
Answer & explanation
Correct answer: option 4
20 : 30 :: 42 : 56 :: 72 : ?
The logic followed here is :
20 + 10 = 30
and
42 + 10 + 4
42 + 14 = 56
Similarly
72 + 10 + 4 + 4
72 + 10 + 8 = 90