The 7th term and 13th term of an AP is 23 and 41 respectively. Find 21st term

a+6d=23. (1)
a+12d=41. (2)
Solving a &b simultaneously
-6d=-14
d=14/3
Putting the value of d in equation(1)
a+6*14/3=23
a+28=23
a=-5
Therefore,
21st term=-5+21*14/3
=93. Ans