Apet shop has 25 dogs at the start of the year. in january, 5 dogs were sold and 3 dogs were bought. in february, 8 dogs were sold and the store took delivery of some new dogs. at the start of march, the number of dogs in the pet shop was the same as the beginning of the year. determine the number of pets bought in february.

The number of dogs the store bought in March was 10.

1)Ok we know that at the start of march, they had the same number of dogs as in the start of january which is 25 dogs. 

2) In january 5 dogs were sold so that means that we now only have 20 dogs

3) They bought back 3 new dogs in january so that means they now have 23 dogs

4) In february 8 dogs were sold. So we do 23-8=15 dogs. They now have 15 dogs left. 

5) Now they're buying dogs so that the total number of dogs in their possession is 25 again. 25-15 is the difference needed to get back 25. 
25-15=10 dogs. They bought 10 dogs at the beginning of march.