Correct Answer - Option 3 : 77
Given :
In an exam B scored 50% more marks than A and 40% fewer marks than C, D scored 18% more marks than B.
Calculations :
Let the marks of A in the exam be 100
B's marks = 100 + 50% of 100 (B scored 50% more than A)
⇒ 150
It is given B scored 40% fewer marks than C that means B scored 60% of C's score.
B's marks = 60% of C's score
60% of C's score = 150
C's score = 250 marks
D's score = 150 + 18% of 150 (D scored 18% more than B)
⇒ 150 + 27
⇒ 177 marks
D score = 177 and A score = 100
Required per cent = (177 - 100)/(100) × 100
⇒ 77%
∴ Option 3 will be the correct choice.