Question

A's marks in Biology are $20$ less than 25% of the total marks obtained by him in Biology, Maths and Drawing. if his marks in Drawing be $50$, what are his marks in Maths?

• A. $40$
• B. $45$
• C. $50$
• D. cannot be determined

Answer 1

The correct option is D cannot be determined

Let marks in Biology$=B$ , Maths$=M$, Drawing$=D$

given that , $D=50$ and that

$B=25\%of(B+M+D)-20$

$B=\frac{25}{100}(B+M+D)-20$

$B+20=\frac{1}{4}(B+M+50)$

$4B+80=B+M+50$

$3B+30=M$

$\therefore$ maths marks cannot be known without knowing $B$