Q8 of 38 Page 5


An A.P consists of 60 terms. If the first and the last terms be 7 and 125respectively, find 32 ndterm.

Given: n = 60

T 1 = 7
T 60 = 125

We know that,

T n = a + (n – 1)d

T 1 = a + (1 – 1)d = a = 7

And,

T 60 = a + (60 – 1)d

T 60 = a + 59d = 125
T 60 = 7 + 59d = 125
59d = 125 – 7 = 118
T 32 = a 1 + (32 – 1)d = a 1 + 31d = 7 + 31(2) = 7 + 62
Hence, T 32 = 69.

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