Which term of AP 72,68,64,60,… is 0?

1.	Which term of AP 72,68,64,60,… is 0?
Answer» In the given AP, first term, a = 72 and common difference, d = (68 - 72) = -4. Let its T_n= 0 \(\Rightarrow\) a + (n - 1) d = 0 \(\Rightarrow\) 72 + (n - 1) x (-4) = 0 \(\Rightarrow\) 76 - 4n = 0 \(\Rightarrow\) 4n = 76 \(\Rightarrow\) n = 19 Hence, the 19^th term of the given AP is 0.

Answer»

In the given AP, first term, a = 72 and

common difference, d = (68 - 72) = -4.

Let its T_n= 0

\(\Rightarrow\) a + (n - 1) d = 0

\(\Rightarrow\) 72 + (n - 1) x (-4) = 0

\(\Rightarrow\) 76 - 4n = 0

\(\Rightarrow\) 4n = 76

\(\Rightarrow\) n = 19

Hence, the 19^th term of the given AP is 0.

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