Question

To find the 15th term of the A.P. 3,8,13,18.....

Answer 1

Given :

• A.P. 3,8,13,18.....

To find :

• the 15th term

Solution :

The given sequence is in A.P.

its first term a 3

d = 8 - 3

d = 5

t15 = ?

tn = a + (n -1)d

t15 = a + (15 - 1) d

t15 = 3 + 14 × 5

t15 = 3 + 70

t15 = 73

∴ 15th term is 73

Extra formula's :

• t_n = a + ( n - 1 ) d

• S_n = n/2 [ 2a + ( n - 1 ) d ]

• S_n = n/2 ( a + 1 )

Answer 2

Answer:

73

Step-by-step explanation:

formula:

(term x 5)-2

(15 x 5 ) -2

75 - 2

73