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 1 and 3 is not allowed)
(1, 8, 3)
(2, 21, 5)

Logic: (1st number + 2nd number)$$\times$$​ (2nd number - 1st number)

Set I. (1, 8, 3)

$$(1 + 3) \times(3-1)\\ \ \\ =4 \times2 \\ \ \\=8$$​​
Set II. (2, 21, 5) 

​$$(2+5) \times(5-2)\\ \ \\=7\times3\\ \ \\=21$$ 

By option (a):  (5, 112, 11)​

​$$(5 + 11)\times(11-5)\\ \ \\ 16 \times6\\ \ \\96\not=112$$ 

By option (b):   (4, 33, 7)

$$(4 +7)\times(7-4)\\ \ \\11\times3\\ \ \\33=33\ \text{Follows}$$  

$$(2+3)\times(3-2)\\\ \\5\times1\\ \ \\5\not=26$$​

By option (d):  (7, 128 ,10)

​$$(7+10)\times(10-7)\\ \ \\ 17 \times3\\ \ \\51\not=128$$ 

Thus, correct option is  (b).

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