Question

find the number of terms in each of the following AP's..7, 13, 19....205​

Answer 1

Answer:

• Number of terms = 34

Step-by-step explanation:

Given:

• First term = a = 7
• Common difference = d = 13 - 7 = 6
• Last term = aₙ = 205

To find:

• Number of terms = n = ?

Solution:

For solving such questions use the below formula:

aₙ = a + (n - 1)d

Substitute given values in this Equation

aₙ = a + (n - 1) d

⇒ 205 = 7 + (n - 1) 6

⇒ 205 - 7 = 6(n - 1)

⇒ 198 = 6 × (n - 1)

⇒ 198 ÷ 6 = (n - 1)

⇒ n - 1 = 33

⇒ n = 33 + 1

⇒ n = 34

∴ The number of terms = 34