Question

The sum of all the ten numbers of an AP is485 of its last term is 71 first term and the common difference of the AP

Answer 1

Sn=n/2(a+l)
485=5(a+71)
485/5=a+71
97-71=a
a=26
L=a+(n-1)d
71-26=9d
45/9=d
d=5
Solution :
A=26
D=5