Sophia has three stickers for every two stickers that Ethan has.
If Sophia gives Ethan 16 of her stickers, then Ethan will have twice as many stickers as Sophia has.
How many stickers do Sophia and Ethan have all together?

40

Step-by-step explanation:

Let number of stickers Sophia has be "x" and number of stickers Ethan has be "y"

Now,

Sophia has 3 for every 2 ethan has, that means

3x = 2y

When sophia gives 16, she will have:

3x - 16

Ethan, after getting 16, will have:

2y + 16

This trade will make Ethan to have TWICE, so we can write:

2(3x-16) = 2y + 16

Now, the 1st equation can be written as:

3x = 2y

x = 2y/3

Now replacing this into 2nd, we solve for y:

So, x is:

Ethan and Sophia has:

24 + 16 = 40 stickers altogether