Question

The 10th and 18th terms of an A.P. are 41 and 73 respectively. Find the 26th term.

Answer 1

$a_{10}=a+9d=41.........\left(1\right)a_{18}=a+17d=\mathrm{72.........}\left(2\right)\left(1\right)-\left(2\right)a-a+9d-17d=41-738d=32d=4a+36=41\text{(Using equation 1)}a=5then{a}_{26}=5+25\times 4=5+100=105$