Question 1148672
As written,
1-0.15*120/360


Easier to see as {{{1-0.15*120/360}}},
easily simplifiable before finish computing.


{{{1-0.15*120/360}}}

{{{1-0.15*12/36}}}

{{{1-0.15*1/3}}}

{{{1-0.15/3}}}

You should be able to finish this...