Correct Option
Let Q's score be represented by x. According to the problem statement, P scored 40 marks more than Q. Therefore, P's score is x+40.
The problem also states that Q scored 10% less marks than P. This implies that Q's score is 90% of P's score. We can set up the equation as follows:
x=90% of (x+40) x=10090(x+40)
To solve for x:
100x=90(x+40) 100x=90x+3600 100x−90x=3600 10x=3600 x=103600 x=360
Thus, Q scored 360 marks.
Incorrect Options
Options 2 (380), 3 (400), and 4 (420) are incorrect because they do not satisfy the conditions given in the problem. If any of these values were Q's score, the relationship that Q scored 10% less than P (where P scored 40 more than Q) would not hold true upon verification. For instance, if Q scored 380, P would score 420. 10% less than 420 is 420×0.90=378, which is not 380. Similar discrepancies arise with 400 and 420.