0 reads0 ratings0 helpful
What is the (20)th term of the AP (-5,-2,1,4,\ldots)?एपी (-5,-2,1,4,\ldots) का (20)वाँ पद क्या है?
Answer and explanationउत्तर और व्याख्या
Correct answer:सही उत्तर: 5252
The first term is \(a=-5\), and the common difference is \(d=-2-(-5)=3\). Hence, \(a_{20}=a+(20-1)d=-5+19\times3=52\). Therefore, 52 is correct. Choosing 49 means counting only 18 intervals, but there are 19 intervals from the first term to the 20th term. Exam tip: Use \(a_n=a+(n-1)d\) and check \(n-1\) before calculating.इस एपी में प्रथम पद \,\(a=-5\) और सार्वांतर \,\(d=-2-(-5)=3\) है। इसलिए \(a_{20}=a+(20-1)d=-5+19\times3=52\)। अतः सही उत्तर 52 है। 49 लेने पर 18 अंतराल गिने जाते हैं, जबकि 20वें पद तक प्रथम पद के बाद 19 अंतराल होते हैं। परीक्षा टिप: \(n\)वें पद के लिए हमेशा \(a_n=a+(n-1)d\) लिखकर पहले \(n-1\) जाँच लें।
Student feedback
Was this question useful?
Was this question useful?
👍 0 Helpful 👎 0 Not helpful
Difficulty
Easy0%
Medium0%
Hard0%
Was the explanation clear?
Yes 0% No 0%
0 responsesStudent Reviews
No published reviews yet.
