In the line 1, three pairs of sneakers add up to 30, so we can see that 1 two pairs of sneakers stand for 10.

In the second line, 1 pair of sneakers plus two kittens with whistles equals 20, which is equivalent to 10 plus two kittens with whistles equals 20, Rosie can be inferred that 1 kitten with whistles only stands for 5.

The third line, 1 Rosie the kitten with a whistle and two pairs of whistles equals 13, which is not wrong for you ~ there are two pairs of whistles, that is, four whistles, which is equivalent to five plus four, which is equivalent to 13, so one whistle represents two.

To sum up, the answer is actually obvious. I don't know if you already know.

Line 4, the ultimate question is coming, everyone must pay attention to the routine! First 1 pair of sneakers, then Rosie the kitten without a whistle! Yes, Rosie the kitten didn't hang a whistle this time! So subtract the number represented by the whistle from the calculation ~ the next operation symbol is not a plus sign, but a multiplication sign! Don't forget the operation sequence we learned in primary school ~ The last pattern is 1 whistle, pay attention to 1 whistle!

So this topic should be converted into such a number:

10+(5-2)×2=?

So the answer is 16!