Question

2. Choose the correct choice in the following and justify:
(i) 30th term of the AP: 10, 7, 4, . . . , is
(A) 97
(B) 77
(C) -77
(D) -87

(ii) 11th term of the AP: -3, -1/2,...,is
(A) 28
(B) 22
(C) -38
(D) -48 1/2​

Answer 1

Answer:

(i) (c)-77

ii) (d) -481/2

Answer 2

Step-by-step explanation:

1) We know that,

a n = a + ( n-1) d

a= 10 ,d= 7-10 = -3 , n = 30

A 30 = 10 + (30 - 1 ) -3

A 30 = 10 + 29 × -3

= 10- 87

= -77

C is the right answer

2) an = a + ( n - 1 ) d

a = -3 , d = -1/2-(- 3) = -1/2+3 = 5/2 = 2.5 , n = 11

a 11 = -3 + ( 11- 1 ) 2.5

a 11 = -3 + 10 × 2.5

= -3 + 25

a 11 = 22

B is the right answer