Select the set in which the numbers are related in the same way as are the numbers of the following sets.
(11, 22, 44) (15, 12, 42)

First number = $$\frac{\left(third\ number - second\ number\right)}{2}$$

(11, 22, 44)

First number = $$\frac{\left(third\ number - second\ number\right)}{2}$$

= $$\frac{\left(44-22\right)}{2}$$

= $$\frac{22}{2}$$

= 11

(15, 12, 42)

First number = $$\frac{\left(42-12\right)}{2}$$

= $$\frac{30}{2}$$

= 15

Option (a) (3, 3, 15)

First number = $$\frac{\left(15-3\right)}{2}$$

= $$\frac{12}{2}$$

= 6

The above given logic is not applicable here. So this is not the correct answer.

Option (b) (21, 42, 63)

First number = $$\frac{\left(63-42\right)}{2}$$
= $$\frac{21}{2}$$

= 10.5

The above given logic is not applicable here. So this is not the correct answer.

Option (c) (12, 24, 39)

First number = $$\frac{\left(39-24\right)}{2}$$

= $$\frac{15}{2}$$

= 7.5

The above given logic is not applicable here. So this is not the correct answer.

Option (d) (18, 8, 44)

First number = $$\frac{\left(44-8\right)}{2}$$

= $$\frac{36}{2}$$

= 18

The above given logic is applicable here. So this is the correct answer.