Question

Can someone answer this for me please and thank you

Answer 1

We see that terms in given sequence decreases by 5 continuously so that means this is an arithmetic progression (AP)

so we will use nth term formula of AP to find the a27

$a_n=a_1+(n-1)d$

n=27 because we need a27

a1= first term = 15

d = common difference = 10-15=-5

Now plug these values into formula $a_n=a_1+(n-1)d$

$a_{27}=15+(27-1)(-5)$

$a_{27}=15+(26)(-5)$

$a_{27}=15-130$

$a_{27}=-115$

So the final answer is $a_{27}=-115$