Saved Bookmarks
| 1. |
Find the middle term of A.P 6, 13,20,........216???? |
| Answer» Here,{tex} a = 6, l =216, d = 13 - 6 = 7{/tex}Let the number of terms be n{tex}l = a + ( n - 1) d{/tex}216 = {tex}6 + (n -1)(7){/tex}216 -6 = {tex}7(n - 1){/tex}{tex}7(n - 1){/tex}= 210{tex}n - 1{/tex}=\xa0{tex}\\frac { 210 } { 7 }{/tex}= 30{tex}n{/tex} = 30 + 1 = 31The middle term will be =\xa0{tex}\\frac { 31 + 1 } { 2 }{/tex}= 16th term{tex}\\therefore{/tex}a16\xa0= 6 +(16 - 1)(7){tex}= 6 + 15 \\times 7{/tex}= 6 + 105= 111Middle term will be 111. | |