Select the set in which the numbers are related in the same way as are the numbers of the following sets, (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 | and 3 is not allowed)
(14, 60, 16)
(25, 80, 15)

(14, 60, 16) 

→ 2 × (14 + 16)

=> 2 × 30 = 60.

(25, 80, 15) 

→ 2× (25 + 15)

=> 2 × 40 = 80.

Let's check all the options as

a) (15, 45, 30) 

→ 2 × (15 + 30)

=> 2 × 45 = 90≠ 45

c) (20, 30, 40) 

→ 2 × (20 + 40)

=> 2 × 60 = 120≠30

d) (21, 120, 15) 

→ 2 × (21 + 15)

=> 2 × 36 = 72≠ 120

Thus, the set of numbers (19, 80, 21) follows the same pattern.

Hence, the correct answer is (b).