RRB NTPC CBT-1 previous year question
The average age of 7 students in a class is 17 years. When a new student join the class, the average age of the class becomes 18 years. Find the age of the new student.
Asked in RRB NTPC 2026 — 16 June Shift 2 · Quantitative Aptitude
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Correct answer: (C) 25 years
Total age of 7 students = 7×17 = 119. New total for 8 students = 8×18 = 144. Age of new student = 144-119 = 25 years.
हिंदी में प्रश्न
एक कक्षा में 7 विद्यार्थियों की औसत आयु 17 वर्ष है। जब एक नया विद्यार्थी कक्षा में शामिल होता है, कक्षा को औसत आयु 18 वर्ष हो जाती है। नए विद्यार्थी की आयु ज्ञात कोजिए।
उत्तर जाँचने के लिए किसी विकल्प पर टैप करें।
उत्तर और व्याख्या देखें
सही उत्तर: (C) 25 वर्ष
7 विद्यार्थियों की कुल आयु = 7×17 = 119। 8 विद्यार्थियों का नया कुल = 8×18 = 144। नए विद्यार्थी की आयु = 144-119 = 25 वर्ष है।
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