According to the question,we are given that,\xa0{tex}S _ { n } = \\frac { 3 n ^ { 2 } } { 2 } + \\frac { 5 n } { 2 } = \\frac { 3 n ^ { 2 } + 5 n } { 2 }{/tex}{tex}\\Rightarrow S _ { n – 1 } = \\frac { 3 ( n – 1 ) ^ { 2 } + 5 ( n – 1 ) } { 2 }{/tex}{tex}= \\frac { 3 \\left( n ^ { 2 } – 2 n + 1 \\right) + 5 n – 5 } { 2 }{/tex}{tex}= \\frac { 3 n ^ { 2 } – 6 n + 3 + 5 n – 5 } { 2 }{/tex}{tex}= \\frac { 3 n ^ { 2 } – n – 2 } { 2 }{/tex}Now,nth term = Tn=Sn-Sn-1={tex}= \\frac { 3 n ^ { 2 } + 5 n } { 2 } – \\frac { 3 n ^ { 2 } – n – 2 } { 2 } = \\frac { 3 n ^ { 2 } + 5 n – 3 n ^ { 2 } + n + 2 } { 2 }{/tex}={tex}\\frac{{6n + 2}}{2}{/tex}=3n+125th term=T25=3(25)+1=75+1=76.