Question

Find the eleventh term from the last term of the AP:
27, 23, 19, ..., -65.
for 1 mark​

Answer 1

Answer:

11th term = 13

Step by Step Explanation:

Let the first term of AP be 'a'

i.e a=27

Let the common difference between two consecutive terms of an AP be 'd'

i.e d= 23-27 = -4

Let the last term(nth term) be tn

i.e tn=-65

Acoording to the formula,

tn= a+(n-1)*d

=> -65=27+(n-1)(-4)

=> -65=27-4n+4

=> 4n=27+4+65

=> 4n=96

=> n=24

n denotes the number of terms in AP

Now let us find 11th term

t11=27+(11-1)(-4)

t11=27-40

t11= -13

The answer is -13