There are 48 photographs in total and he puts them inn 8 equal rows. With this, you have to divide the total amount of photographs (48) by the amount of equal rows (8) to see how many photographs are in each row.
48/8 = 6 photographs in each row.
To check, you can simply do the inverse operation which would be:
6 x 8 = 48
As you can see, the total of 48 still remains.
The answer is:
There are 6 photographs in each row.
