Let total marks be 100
then 75 marks written paper
and 25 marks of course work.
mental test marks = 75 × 1/4 = 18.75
% of 18.75/100 = 1875/10000
reduce to get in fraction form
= 75/400
= 3/16 part
or
direct calculations
1/4 of written = mental marks = 3/4 × 1/4 = 3/16
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