ABC26GN2363 · Percentage

Subject: General Aptitude · Chapter: Percentage · Exam: · Marks: · Difficulty:

In an examination of $n$ questions, a student replied 15 out of the first 20 questions correctly. Of the remaining questions, he answered one-third correctly. All the questions have the same credit. If the student gets 50\% marks, the value of $n$ is

(a)20

(b)40

(c)50

(d)100

Answer

Answer (as printed): C

Explanation

$$\begin{aligned} & 15+\frac{1}{3}(n-20)=50 \% \text { of } n=\frac{50}{100} n=\frac{n}{2} \\ & \Leftrightarrow 90+2 n-40=3 n \quad \Leftrightarrow \quad n=50 . \end{aligned}$$

Explanation as extracted from the printed page; notation may be imperfect.

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