RPF Constable practice question
Find the sum of the first 10 terms of the arithmetic progression 12, 15, 18, ….
From a RPF Constable Quantitative Aptitude practice set · Quantitative Aptitude
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Correct answer: (B) 255
a = 12, d = 3, n = 10. Sₙ = n/2 × [2a + (n − 1)d] = 10/2 × [24 + 9 × 3] = 10/2 × 51 = 255.
हिंदी में प्रश्न
समांतर श्रेढ़ी 12, 15, 18, … के प्रथम 10 पदों का योग ज्ञात कीजिए।
उत्तर जाँचने के लिए किसी विकल्प पर टैप करें।
उत्तर और व्याख्या देखें
सही उत्तर: (B) 255
a = 12, d = 3, n = 10। Sₙ = n/2 × [2a + (n − 1)d] = 10/2 × [24 + 9 × 3] = 10/2 × 51 = 255।
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