Q.

Which term of the A.P. –29, –26, –23, ..., 61 is 16

1 11th  
2 16th  
3 10th  
4 31st  

Ans.

(2)

Given, a=-29

d=-26-(-29)=-26+29=3d=3

an=16

Here we know, an=a+(n-1)d

16=-29+(n-1)3

16+29=(n-1)3=15

n-1=453=15

15=n-1n=16