charmer treasury bills

sir
if there is opening and closing for treasury bills and you haven’t told that these are taken as cash and cash equivalents so we will bring the net figure to just investing activities?

or we need to bring it to opening and closing of cash and cash equivalents
like
short term treasury bills C/B 120 O/B 50
cash nil 122
overdraft 136 nil

c & c eq bf (50+122) 172
c& c eq cf(120-136) (16)
is this wrong?

or

c & c eq bf 122
c & c eq eq (136)