Question

If the 11th term of an A.p is 44 and 16th term is 19 , find the 20th term and the A.P

Answer 1

a+10d=44----------------1

a+15d=19-----------------2

on solving 1 and 2

you get d= -5

and a= 94

hope you find this solution useful

Answer 2

Answer:

We have the 11th term: a+10d= 44 ; and we have the 16th term: a+15d= 19

Therefore when we eliminate the two equations above we get:

-5d= 25 ; therefore d= -5; {eliminating by subtracting the 2 eq}

Thus by applying the value of d in any of the above equations:

a+10(-5)= 44

a-50= 44

a= 94

therefore now we apply the value of a and d in the 20th term:

=a+19d

=(94) +19(-5)

= 94-95

=-1  => This is the 20th term of the AP