Question

Find the 31 term of an AP whose 11 term is 38 and the 16 term is73

Answer 1

Answer:

472

Step-by-step explanation:

Tn=a+(n-1)d

T11=a+10d=38.........(1)

T16=a+15d=73.........(2)

solve 1 and 2

we get a=-32    and d=7

T73=-32+72*7

     =472

Answer 2

Answer:

31st term = 178

Step-by-step explanation:

T11 = a + 10d .......(1)

T16 = a + 15d .......(2)

Subtracting equation (2) from (1),

-5d = -35

d = 7

Substituting value of d in equation (1)

a + 70 = 38

a = -32

To Find:

T31 = a + 30d

T31 = -32 + 210

T31 = 178