The first one: let's set the price of coat as X, then the price of trousers is 60%X, then 60%X+X=880.

X=550, pants is 330.

The second way: since 1500 heads are sold, the proportion is 37.5%, so we assume that the total number is X, then 37.5%X= 1500, and the total number of heads is 4000, so the rest is 2500.

Third: Is the topic wrong?

The fourth method: the number with the percent sign removed becomes one hundred times the original number. Since it is increased by 34.65, it is 100X-X=99X=34.65, and then X=0.35, which is 35%.