Question

Pls answer Q24.
a class 10 question​

Answer 1

the ans is a
let the ap be 1,2,3,.....10 b
d=1

S10 =55
Sn-1=45
Sn-2=36
d=Sn-2Sn-1+Sn-2
d=55-2(45)+36
d= 55-90+36
d=91-90
d= 1

i hope it is useful...