The given sequence is 25, 10, 4.
Notice that this is a geometric sequence because here we have equal common ratio.
So, common ratio : r =
=
= 0.4
So, each term is 0.4 times of it's previous term.
Hence, to get the next term of this sequence, multiply 0.4 with the third term 4.
So, fourth / next term = 4* 0.4 =1.6
Hence, next term of this sequence is 1.6.
Hope this helps you!