Answer:
30 minutes.
Explanation:
You can make a proportion, which would be 10 selfies : 12 minutes. The second one will be 25 selfies : x minutes.
They have to be equal, since it is given that the rate stays the same. So 10:12=25:x
A proportion can be written as a fraction, so 10/12=25/x.
Cross multiply, and you get 10*x=12*25, or 10x=300.
Now divide both sides by 10 to get x=30.