Question

Can someone help me with Q.27 first option and Q.28 second option.​

Answer 1

it is in A.P

to find the value of n use

sum=n/2(2a+(n-1)d)

287=n/2(2*1+(n-1)3)

574=2n+3n^2-3

n=21

now use nth term =a+(n-1)d

we get x= 41