Question

A student appeard in the Mock CAT. The test paper contained 3 sections namely QA, DI and VA. The percentage marks in VA was equal to the average of the percentage marks in all the 3 sections. Coincidentally, if we reverse the digits of the percentage marks of QA we get the percentage marks of Dl. The percentage marks in VA scored by the student could be :

• A. 48
• B. 66
• C. 69
• D. 81

Answer 1

The correct option is B 66

Let the percentage marks in QA = (10a + b)%
Let the percentage marks in DI = (10b + a)%
Let the percentage marks in VA = x%
then $\frac{(10a+b)+x+(10b+a)}{3}=x\Rightarrow 11a+11b+x=3x\Rightarrow x=\frac{11}{2}(a+b)$
Thus the percentage of the VA section is a multiple of 11.