Question

The first term of AP is 5 and 100th term is -292. Find 50th term of this AP (Ans:-142)[answer can be near this number]​

Answer 1

Given,

a1 = 5

a100 = -292

Formula = a + (n-1) d

a1 = 5

Therefore a = 5                    --eq(1)    

lly,

a100 = a + (n-1)  d

-292 = a + (100-1) d

-292 = a + 99d                      --eq(2)

If we subtract eq(1) and eq(2)

We get d = -3

For, a50

a50 = a + (50-1) d

       = 5 + (50-1) -3

       = 5 + (-147)

       = -142