Question

Find B D.
B: {−2, −1, 1, 4, 7, 12}
D: {numbers divisible by 3 from 1 to 15}

Answer 1

Is this "Find B D" meant to be "Find B intersect D" or perhaps "Find B union D"?

Answer 2

sorry about that it's B union D...

Answer 3

@Directrix

Answer 4

The union will be all the elements in set B together with all the elements in set D. If there is a duplicate, just write it one time in the union.

Answer 5

So, I would start with all the elements in set B and then see what is in set D that is different and add it to the list of elements for the union.

Answer 6

@Jezz007 --> What numbers come from this: {numbers divisible by 3 from 1 to 15}. List them here. Then, I'll get the elements from B, and we'll put them together.

Answer 7

1 and 3 ??

Answer 8

One is divisible by 3 (answer of 1/3) but in this context, divisible by 3 means multiples of 3. Sorry - I forgot to say that before you started working.

So in set D, 3 is divisible by 3 because the quotient is 1.
Is 4 divisible by 3? No
Is 5 a multiple of 3? No
Is 6 a multiple of 3? Yes because 6/3 = 2 with no remainder.

So far, we have 3 and 6.

What are the others after 6?

Post here.

When we get them all, we'll put them in ascending order (smallest to largest) for the union.

Answer 9

You are working in just set D. Don't look at set B right now.

Answer 10

So far, we have 3 and 6 from set D. There are 3 others. Do you know how to find them?

Answer 11

dividing them right?

Answer 12

9, 12, and 15?

Answer 13

@Directrix

Answer 14

Right.

Answer 15

From D, we have 3, 6, 9, 12, and 15.
From B, we have −2, −1, 1, 4, 7, 12.

Agree?

Answer 16

yup

Answer 17

B U D = { -2, -1 , 1, 3 , 4, 6, 7, 9, 12, 15 }

Check -> we don't want to leave out anything.

Answer 18

its good

Answer 19

Okay. I was just thinking that the intersection of B and D would just be the number 12. Alrighty, then.

Answer 20

thanks buddy :)

Answer 21

Glad to help.