Question

o. which of term of Ap - -1, -3, -5,-7 , is - 151 ​

Answer 1

Step-by-step explanation:

In the given problem, we need to find the number of terms in an A.P

-1, -3, -5, -7 …

We are given,

an=-151

Let us take the total number of terms as n.

So,

First term (a) = −1

Last term (an) = −151

Common difference (d) = -3 - (-1)

= -3 + 1

= -2

Now as we know

an=a+(n-1)d`

SO for the last term

-151=-1+(n-1)(-2)

-151 = -1 - 2n + 2

-151 = - 2n

-2n = 151 - 1

On further simplifying, we get,

-2n = -152

n=-152-2

n = 76

Therefore, the total number of terms of the given A.P. is n = 76

Answer 2

Answer:

a = -1 , d= -3 - (-1) = -3+1 = -2 ,an = -151

an = a + (n-1)d

-151 = -1+(n-1)-2

-151+1 = (n-1)-2

$\frac{ - 150}{-2} = n - 1$

75 = n-1

n = 75 +1

n = 76