In the following number-pairs, the second number is obtained by applying certainmathematical operations to the first number. Select the set in which the numbers arerelated in the same way as are the numbers of the following sets.(NOTE: Operations should be performed on the whole numbers, without breaking downthe numbers into their constituent digits. E.g. 13 – Operations on 13 such asadding/subtracting/multiplying to 13 can be performed. Breaking down 13 into 1 and 3and then performing mathematical operations on 1 and 3 is not allowed.)

10 - 15

19 - 24​​

Given: 

10 - 15

19 - 24

Logic: 1st number + 5 = 2nd number

For, 10 - 15

10 + 5 = 15

For, 19 - 24

19 + 5 = 24

Now, we check each options.

Option (a): 63 - 68 (Follow)

63 + 5 = 68

Option (b): 42 - 48 (Not Follow)​

42 + 5 $$\neq$$ 48​

Option (c): 1 - 7 (Not Follow)​

1 + 5 $$\neq$$​ 7

Option (d): 51 - 57 (Not Follow)​

51 + 5 $$\neq$$ 57

Thus, correct option is (a).