The number of subsets of a set with n elements is 2^n. Here, n=4, so the number of subsets is 2^4 = 16.

The number of subsets of a set with n elements is 2^n. Here, n = 3, so the number of subsets is 2^3 = 8.

The only subset that does not contain y is {∅} and {x}. Total = 2.

There are 360 degrees in a circle, and 360/15 = 24 time zones.

The Earth is divided into 360°, and if each time zone is 15° apart, then the number of time zones is 360° / 15° = 24.

The Earth is 360 degrees, and if each time zone is 15 degrees, then 360 / 15 = 24 time zones.

The Earth is 360 degrees, and 360/15 = 24 time zones.

The Earth is divided into 360° of longitude. 360° / 15° = 24 time zones.

There are 360° in a circle, and with each time zone covering 15°, there are 360/15 = 24 time zones.

There are 24 standard time zones in the world, corresponding to each hour of the day.

Product B sold 25 units in Q1, 25 in Q2, 25 in Q3, and 25 in Q4, totaling 100 units.

Nitrogen has an atomic number of 7, with the electron configuration of 1s² 2s² 2p³, resulting in 3 unpaired electrons in the 2p subshell.

The number of ways to choose 10 items from 15 is given by 15C10 = 15C5 = 3003.

The number of ways = 5C2 * 4C2 = 10 * 6 = 60.

The number of ways to select 2 boys from 5 is C(5, 2) and 2 girls from 5 is C(5, 2). Total = C(5, 2) * C(5, 2) = 10 * 10 = 100.

The number of ways is C(6,2) * C(4,2) = 15 * 6 = 90.

The number of ways is 5C2 * 5C2 = 10 * 10 = 100.

The number of ways is 5C2 * 6C3 = 10 * 20 = 200.

The number of ways is 5C2 * 7C3 = 10 * 35 = 350.

The number of ways is 6C2 * 4C3 = 15 * 4 = 60.

The number of ways is 8C2 * 6C3 = 28 * 20 = 560.

The number of ways to select 2 boys from 5 is 5C2 and 3 girls from 7 is 7C3. Total = 5C2 * 7C3 = 10 * 35 = 350.

The number of ways is 6C2 * 4C3 = 15 * 4 = 60.

The number of ways is 6C2 * 8C3 = 15 * 56 = 840.

The number of ways to select 2 men from 5 is 5C2 and 3 women from 6 is 6C3. Total = 5C2 * 6C3 = 10 * 20 = 200.

The number of ways to choose 2 from 5 is C(5,2) = 10.

The number of ways to select 2 students from 5 is given by 5C2 = 10.

The number of ways to select 2 from 8 is C(8, 2) = 28.

The number of ways to select 3 books from 10 is given by 10C3 = 120.

The number of ways to arrange 5 people is 5! = 120.