In an AP, (a_1=13) and (d=8). What is the (10)th term?
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Answer and explanation
Correct answer: 85
The nth term of an AP is \(a_n=a_1+(n-1)d\). Therefore, \(a_{10}=13+(10-1)\times 8=13+72=85\). Hence, 85 is correct. The value 93 results from incorrectly adding \(10d\) instead of \((10-1)d\). Exam tip: for the nth term, always use \((n-1)\) common differences.
Frequently asked questions
What is the correct answer to this question?
85
Why is this the correct answer?
The nth term of an AP is \(a_n=a_1+(n-1)d\). Therefore, \(a_{10}=13+(10-1)\times 8=13+72=85\). Hence, 85 is correct. The value 93 results from incorrectly adding \(10d\) instead of \((10-1)d\). Exam tip: for the nth term, always use \((n-1)\) common differences.
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Arithmetic Progressions (AP). Topic: Finding the $n$th term of an AP.
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