The second number in the given number pairs is obtained by performing certain mathematical operation(s) on the first number. The same operation(s) are followed in all the number pairs, EXCEPT one. Find that odd number pair.

Select the option that is related to the fifth term in the same way as the second term is related to the first term and the fourth term is related to the third term.
 DENIAL : IANDEL :: OBJECT : ECJOBT :: FLAVOR : ?

If M denotes ‘−’, N denotes ‘÷’, O denotes ‘×’ and P denotes ‘+’, then what will come in place of ‘?’ in the following equation?
(38 O 13) N 19 M 27 P (38 O 3) P 43 M 68 = ?

Select the odd group of numbers. (NOTE: Operations should be performed on the whole numbers, without breaking down the numbers into its constituent digits. E.g.13 – Operations on 13 such as adding /subtracting /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)

(22, 9, 198)

Which of the following numbers will replace the question mark (?) in the given series?
 1331, 2197, ?, 6859

Select the number from among the given options that can replace the question mark (?) in the following series.
 5, 10, 17, 26, 37, 50, ?

Which letter-cluster will replace the question mark (?) to complete the given series?

MDSA, KERC, ?, GGPG, EHOI

Which of the following interchange of numbers and mathematical signs would make the given equation correct?
72 ÷ 8 × 9 − 36 + 20 = 80