Question

Which term of the Ap 1,4,7,.... is 25

Answer 1

Answer :-

• The 9th term of the AP is 25.

Given :-

• An AP 1, 4, 7

To Find :-

• Which term of the AP is 25.

Solution :-

Here

• First term T1 = 1
• Second term T2 = 4
• Common difference d = T2 - T1 = 4 - 1 = 3

As we know that

• Tn = a + (n - 1)d

According to question :-

⇒ Tn = a + (n - 1)d

⇒ T25 = 1 + (n - 1)3

⇒ 25 = 1 + 3n - 3

⇒ 25 = 1 - 3 + 3n

⇒ 25 = 3n - 2

⇒ 3n = 25 + 2

⇒ 3n = 27

⇒ n = 27/3

⇒ n = 9

Hence, the 9th term of the AP is 25.

Answer 2

Solution is given in the above attachment..