Question

the common difference in an ap is -2 if its first term is 100 and the last term is - 10 how many term are there in the AP​

Answer 1

Answer:

56

Step-by-step explanation:

Let there are n terms:

nth term is given by a + (n - 1)d, here,

⇒ - 10 = 100 + (n - 1)(-2)

⇒ - 10 - 100 = (n - 1)(-2)

⇒ - 110 = (n - 1)(-2)

⇒ -(110)/(-2) = n - 1

⇒ 55 = n - 1

⇒ 55 + 1 = 56 = n