Question

Which term of A. P. 5, 15, 25, ............ will be 130 more than its ${31}^{st}$ term ?

Answer 1

Ap is 5,15,25.......
a=5 and d=15-5=10
31st term=a+30d
=5+30$\times$10
=5+300
31st term =305
an=305+130
=435
a+(n-1)d=435
5+(n-1)10=435
(n-1)10=435-5
(n-1)=$\frac{430}{10}$
n-1=43
n=44
It means the 44th term of the given AP will be 130 more than its 31st term.