If (a_n=7-3n), what is the (22)nd term of the AP?
Answer and explanation
Correct answer: \(-59\)
Using the given direct formula \(a_n=7-3n\), substitute \(n=22\): \(a_{22}=7-3(22)=7-66=-59\). Hence, \(-59\) is correct. An answer such as \(-57\) can result from an error in multiplying \(3\times22\) or in subtraction. Exam tip: In a direct formula, substitute the term number for \(n\) and perform multiplication before subtraction.
Frequently asked questions
What is the correct answer to this question?
\(-59\)
Why is this the correct answer?
Using the given direct formula \(a_n=7-3n\), substitute \(n=22\): \(a_{22}=7-3(22)=7-66=-59\). Hence, \(-59\) is correct. An answer such as \(-57\) can result from an error in multiplying \(3\times22\) or in subtraction. Exam tip: In a direct formula, substitute the term number for \(n\) and perform multiplication before subtraction.
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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