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 Drawings be 50, what are his marks in Maths ?

Answer: Option D

Let B + M + D = $$x$$
Then,
B = 25 of $$x$$ - 20
$$\begin{array}{rl}& =\left(\frac{25x}{100}-20\right)\\ & =\left(\frac{x}{4}-20\right)\end{array}$$
And D = 50
∴ $$\frac{x}{4}$$ - 20 + M + 50 = $$x$$
or M = $$\left(\frac{3x}{4}-30\right)$$
So, marks in Maths cannot be determined.