Question

Find the 31st term of an AP whose 11th term is 38 and the 16th term is 73.

Answer 1

let first term of Ap is a and common difference is d

use formula

tn=a+(n-1) d

now

t11=a+(11-1) d=a+10d=38

same way

t16=a+15d=73

solve this equation then

a=-32 and d=7

now t31=a+30d=-32+210=178

Answer 2

31 term is 178........