Find the twenty fifth term of the A.P. : 12, 16, 20, 24, ..........

108

112

116

120

Correct Answer: Option(a)

Solution: Let $a$ be the first term and $d$ be the common difference of given AP. Hence $a=12$ and $d=16−12=4$. $t_{n}=a+(n−1)d$ $⇒t_{25}=12+24×4$ $⇒t_{25}=12+96$ $⇒t_{25}=108$