How many trains do not stop at either of these stations on that day?

Start by assigning letters to all the different possibilities we can think of (draw a diagram if it helps).
It won't matter if we don't use them all. At this point they are unknowns, so lets use a letter to represent them.

#T# = total number of trains
#O# = number of trains stopping only at Oaklands
#B# = number of trains stopping only at Brighton
#N# = number of trains stopping at neither
#U# = number of trains stopping at both

#barO# = number of trains not stopping at Oaklands
#barB# = number of trains not stopping at Brighton
................................................

List what we are told:

#U = 60#

#O + B = 60#

#barO = T/5#

#barB = 45#

#T = N+O+B+U#
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Write equations for things we know. It doesn't matter if they look a bit complicated at first. Try different ideas. Put the values in later, after rearranging the equations.
We are told that #O+B=60# is so lets try finding what they are in terms of other unknowns (so we can maybe add them... )

#barO = N + B = T/5# ....(i.e. trains stopping at Neither + only B )

#N+B = 1/5(N+O+B+U) #

#N+B = 1/5(N+60+60) #

#N+B = N/5+120/5 #
#B = 24 - 4/5N# ..........................................(1)
...................................................

And:

#barB = N + O = 45# ....(trains stopping at neither + only O )

# O = 45 - N # ................................................(2)
....................................................

But #B + O = 60#, so

# 24 - 4/5N + 45 - N = 60# .........adding (1) and (2)

# - 4/5N - N = 60 - 24 - 45#

# - 1.8N = -9#

# N = (-9)/-1.8#

# N = 5#

Note that it is now easy to find B (=20 ) and O (=40 ) by using #N=5# in eqns (1) and (2)