In an A.P. if $a = - 7$ , $d = 5$ , find $T_{12}$

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Solution

We know that the formula for the nth term is $t_{n} = a + (n - 1) d$ , where $a$ is the first term, $d$ is the common difference.

It is given that the first term is $a = - 7$ and the difference is $d = 5$ , therefore,

$t_{12} = a + (n - 1) d = - 7 + (12 - 1) 5 = - 7 + (11 \times 5) = - 7 + 55 = 48$

Hence, $t_{12} = 48$

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