Multiple choice

Which term of the series $5, 8, 11, 14,$ .. is $320$ ?

  1. ${ 104 }^{ th }$
  2. ${ 105 }^{ th }$
  3. ${ 106 }^{ th }$
  4. ${ 64 }^{ th }$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

This is an arithmetic progression with a=5, d=3. Formula: a_n = a + (n-1)d. 320 = 5 + (n-1)3. 315 = (n-1)3. 105 = n-1. n = 106.

AI explanation

The given series is an arithmetic progression with a first term of 5 and a common difference of 3. Using the formula for the nth term, Tn = a + (n - 1)d, we set 320 = 5 + (n - 1) x 3. Solving this equation yields 315 = (n - 1) x 3, so n - 1 = 105, meaning n is 106.

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