Question

5. If the first two terms of an A.P.are 100 and 105, then what is the 21st term
of this A.P.?
(A) 200 (B) 205 (0) 190 (D) 195
Here, d=5​

Answer 1

Answer:

D

Step-by-step explanation:

First find common difference which is difference of any two consecutive terms , so

$d = 105 - 100 = 5$

Now first term a = 100

$a_n = a + (n - 1)d \\ a_{20} = 100 + (20 - 1)5 \\ a_{20} = 195$

Answer 2

Answer:

Step-by-step explanation: