Acell has 2n=8 many chromosomes will this cell have in anaphase1,anaphase2,metaphase2? (meiosis)

The answer is 8 (anaphase 1), 8 (anaphase 2), 4 (metaphase 2).

Meiosis is a cell division which results in a reduction of the number of chromosomes in half and it consists of meiosis I and meiosis II.
Before meiosis I begins, the cell is diploid (2n) and there are 8 chromosomes. In anaphase I, the sister chromatids separate from each other to the opposite sides of the cells, and after that, there are 8 chromosomes and 16 chromatids. After telophase I, there are, however, 4 chromosomes that enter meiosis II.

Meiosis II is similar to mitosis. So, in metaphase II there is the same number of chromosomes - 4 chromosomes. But, the chromosome number must double so in anaphase II there will be in total 8 chromosomes - 4 chromosomes at the one side of the cell and the 4 on the other side. After telophase II, there are 4 chromosomes.