Q5 of 105 Page 139

Find the number of terms in each of the following APs :
7, 13, 19, . . ., 205

Given first term (a) = 7

Common difference (d) = n₂-n₁ = 13 - 7 = 6

a_n = 205

⇒ a_n = a + (n-1)d

205 = 7 +(n-1) 6

198 = (n-1) 6

(n-1) = 33

n = 34

Therefore 205 is 34^th term of the series.

Find the respective terms for the following APs.

a₂ = 38, a₆ = -22, find a₁, a₃, a₄, a₅

Which term of the AP : 3, 8, 13, 18, ….. , is 78

Find the number of terms in each of the following APs :

18, 15, 13 …. , -47

Check whether, -150 is a term of the AP: 11, 8, 5, 2 ….

Questions · 105

6. Progressions

1 1 1 1 2 2 2 2 2 3 3 3 3 4 4 4 4 4 4 4 4 4 4 4 4 4 1 2 2 3 3 3 3 3 4 5 5 6 7 8 9 10 11 12 13 14 15 16 17 1 1 1 1 2 2 2 3 3 3 3 3 3 3 4 5 6 7 7 8 9 10 11 12 13 14 1 1 1 2 2 2 2 3 3 3 3 3 3 3 3 3 4 1 1 1 1 2 3 3 4 4 4 5 6 7

Find the number of terms in each of the following APs :7, 13, 19, . . ., 205