Question

Which term of an A.p.16,11,6,....Is -54 ?

Answer 1

Answer:15th term

Step-by-step explanation:

d = term 2 - term 1 = 11 - 16 = -5.

a (first term) = 16

The formula for A.P. is ;

Sn = a + ( n - 1 ) d

where, Sn is the value of nth term ,i.e., -54.

Now , put the values of a , n and Sn in the formula.

      -54 = 16 + ( n - 1 ) (-5)

      - 70 = -5n + 5

       -75 = -5n

        n = 15