Question

Find the sum of the arithmetic progression 60, 57, 54, 51. ........, 0.
a. 627
b. 630
c. 633
d. 636​

Answer 1

Answer:

To find- Sn

Step-by-step explanation:

AP = 60,57,54,51,......,0

a=60

d=57-60 =>-3

l=0

=>a+(n-1)d=0

=>60+(n-1)(-3)=0

=>60-3n+3=0

=>3n=63

=>n=21

S21=21/2(a+l)

=>21/2(60+0)

=>21/2*60

=>21*60

=>1260

Hope this will help you

Please make my answer the braniest

Answer 2

Answer:

$\text{Option B}$

Step-by-step explanation:

Refer to the above attachment