If the sum of terms of an A.P. is given by , where are independent of , then 

a) 
b) 
Common difference of A.P. must be 

c) 
Common difference of A.P. must be 
d) 
First term of A.P. is 
If the sum of terms of an A.P. is given by , where are independent of , then 

a) 
b) 
Common difference of A.P. must be 

c) 
Common difference of A.P. must be 
d) 
First term of A.P. is 