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प्रश्न
In an AP, if d = –4, n = 7, an = 4, then a is ______.
विकल्प
6
7
20
28
उत्तर
In an AP, if d = –4, n = 7, an = 4, then a is 28.
Explanation:
We know that nth term of an AP is
an = a + (n – 1)d
Where,
a = first term
an is nth term
d is the common difference
According to the question,
4 = a + (7 – 1)(– 4)
4 = a – 24
a = 24 + 4 = 28
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