J has 24 cards. He divides them between his brother, his sister, and himself in the ratio 2:1:5. How many cards do they each get?

The total ratio representing the number of cards is 2+1+5=<<2+1+5=8>>8

Since there are 8 parts in a whole, each part represents 24/8=<<24/8=3>>3 cards.
So J's brother gets 3*2=<<3*2=6>>6 cards
J's sister gets 3*1=<<3*1=3>>3 cards
J gets 3*5=<<3*5=15>>15 cards. Answer: \boxed{6,3,15}.

To find out how many cards each person gets, we need to divide the total number of cards (24) according to the given ratio (2:1:5).

Step 1: Calculate the total number of parts in the ratio.
The given ratio is 2:1:5, which totals to 2 + 1 + 5 = 8 parts.

Step 2: Calculate the number of cards each part represents.
To find the value of one part, we divide the total number of cards (24) by the total number of parts (8).
24 cards / 8 parts = 3 cards per part.

Step 3: Calculate the number of cards for each person.
Multiply the number of cards per part by the corresponding ratio number for each person:
- J: 2 parts x 3 cards = 6 cards
- Brother: 1 part x 3 cards = 3 cards
- Sister: 5 parts x 3 cards = 15 cards

Therefore, J gets 6 cards, his brother gets 3 cards, and his sister gets 15 cards.

To find out how many cards J's brother, sister, and himself get, we first need to determine the total number of parts in the ratio, which is 2 + 1 + 5 = 8.

Next, we'll divide the total number of cards (24) by the total number of parts (8) to find the value of one part: 24 ÷ 8 = 3.

Now, we can determine the number of cards each person gets by multiplying the value of one part by the corresponding ratio value.

J's brother gets: 2 parts × 3 cards = 6 cards
J's sister gets: 1 part × 3 cards = 3 cards
J himself gets: 5 parts × 3 cards = 15 cards

So, J's brother gets 6 cards, J's sister gets 3 cards, and J himself gets 15 cards in total.