Question

What does it mean by the first term of each is unity in ARITHMETIC PROGRESSIONS?​

Answer 1

Answer:

The first term of arithmetic progression is 1 and the sum of the first nine terms equal to 369. The first and the ninth term of a geometric progression conicide with the first and the ninth term of the arithmetic progression

Answer 2

Answer:

a=1,d=5

∴a

n

=a+(n−1)d

=1+(n−1)5

a

n

=5n−4

(A)4880=5n−4

5n=4884

n=(

5

4884

)=notaninteger

(B)7881=5n−4

5n=7885

n=(

5

7885

)=1577=integer

(C)5890=5n−4

5n=5894

n=(

5

5894

)=notaninteger

(D)7891=5n−4

5n=7895

n=(

5

7895

)=1579=integer

∗twooptionspossible.